Dividing by 1000

Dividing by 1000
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Dividing by 1000 Summary of 9000 divided by 1000

  • To divide a number by 1000, move all of its digits three place value columns to right.
  • The digit ‘9’ will move from the thousands column to the units column.
  • The digit ‘0’ will move from the hundreds column to the tenths column, immediately after the decimal point.
  • The digit ‘0’ in the tens column will move to the hundredths column.
  • The digit ‘0’ in the units column will move into the thousandths column
  • 9000 ÷ 1000 = 9.000
  • Since the digits after the decimal point are all zeros, we do not write them.
  • 9000 ÷ 1000 = 9.
  • Because 9000 is a whole number, ending in three ‘0’ digits, dividing it by 1000 had the same effect as removing these three zeros.
To divide by 1000, move all digits in a number 3 place value columns to the right.

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Dividing by 1000 Example 604 divided by 1000

  • To divide a number by 1000, move all of its digits 3 place value columns to the right.
  • In this example we have 604 ÷ 1000.
  • The ‘6’ in the hundreds column moves to the tenths column, immediately after the decimal point.
  • The ‘0’ in the tens column moves to the hundredths column.
  • The ‘4’ in the units column moves to the thousandths column.
  • 604 ÷ 1000 = 0.604

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Dividing by 1000: Interactive Questions

Divide Decimals by 1000: Interactive Questions

Dividing by 1000 Worksheets and Answers

How to Divide a Number by 1000

To divide a number by 1000 we move each digit in that number three place value columns to the right.

Dividing a whole number that ends in three zeros by 1000 has the same effect as removing the three zeros.

This trick only works for whole numbers that end in three zeros (or numbers that are multiples of 1000). Here is an example of dividing such a number by 1000.

example of dividing 9000 by 1000

In the example above, each digit in the number 9000 has been moved three places to the right.

The digit of ‘9’ in the thousands column moves into the units column.

When dividing by one thousand, any digit in the thousands column will always move into the units column to the left of the decimal point.

The ‘0’ in the hundreds column moves three places into the tenths column, immediately after the decimal point.

The ‘0’ in the tens column moves three places into the hundredths column.

Finally, the ‘0’ in the units column moves into the thousandths column.

So, 9000 becomes 9.000, which is the same as 9.

If a number only has the digit of ‘0’ after its decimal point, then it is a whole number and we do not write the zeros or the decimal point.

It is easier to write 9 than 9.000.

You may also know that when we divide a whole number ending in three zeros by 1000, that we can simply “remove the zeros” from the end of this number.

This trick will not work if we have a decimal number.

It is important to understand how dividing by 1000 works because not all numbers that we divide by 1000 will end in three zeros.

For example:

dividing 604 by 1000 to get a decimal number

To divide 604 by 1000, we move each digit in 604 three places to the right.

We begin by moving the ‘6’ from the hundreds column three places to the right into the tenths column.

The ‘0’ and the ‘4’ will then follow the 6 in the same order. The ‘0’ moves from the tens column into the hundredths column and the ‘4’ moves from the units column into the thousandths column.

Because there are no longer any digits in the units column, we write in a zero.

And so, 604 ÷ 1000 = 0.604.

We always write a single ‘0’ digit in the units column before the decimal point if there is no other digit remaining to write there. It is not correct to start a number with a decimal point and so we write ‘0.604’ rather than ‘.604’. This avoids confusion in written text involving numbers. It avoids confusion between commas, full stops and decimal points.

A decimal point is small and sometimes not noticed. By including the zero before the decimal point, it helps to identify to the reader that there is likely to be a decimal point after the zero. This is because whole numbers do not start with a zero and the only way for a zero to be the first digit in a number is if it is a decimal number.

In the following example we are dividing a decimal number by 1000.

dividing a decimal number 12.8 by 1000 to get a decimal number

We begin by moving the digit of ‘1’ three places to the right. It moves from the tens column to the hundredths column. The 2 and the 8 will then follow. We move the 2 from the units column to the thousandths column and we move the 8 from the tenths column to the ten-thousandths column.

As there are no longer any digits in either the units column or the tenths column, we write a zero in each of these spaces.

Therefore, 12.8 ÷ 1000 = 0.0128

In the following example we are dividing a decimal number that is less than 1 by 1000.

dividing a decimal number 0.5 by 1000 to get another decimal number

To do this, we move the digit of ‘5’ three places to the right, from the tenths column to the ten-thousandths column.

Because there are no digits in either the tenths column, the hundredths column or the thousandths column, we write a zero in each of these columns to show that their values are zero.

Therefore, 0.5 ÷ 1000 = 0.0005.

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Now try our lesson on Tenths and Hundredths where we understand more about the decimal place value columns of tenths and hundredths.

Dividing Decimals by 10

Dividing Decimals by 10
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Dividing by 10 example

  • To divide a number by ten, move each digit in that number one place to the right.
  • We will look at the example of dividing 30 by 10.
  • ‘3’ moves from the tens column into the units column.
  • The ‘0’ moves from the units column past the decimal point into the tenths column.
  • 30 ÷ 10 = 3.0
  • If the only digit after the decimal point is a zero, we do not write it.
  • 30 ÷ 10 = 3
To divide a number by 10, move all of its digits one places to the right.

Dividing by 10 has the effect of removing a zero digit from a number that has a ‘0’ in its units column.

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Dividing by 10 to get a decimal Example

  • To divide a number by 10, all digits of this number move one place value column to the right.
  • In this example we will divide the number 91 by 10.
  • The digit ‘9’ moves from the tens column to the units column.
  • The digit ‘1’ moves from the units column to the tenths column.
  • 91 ÷ 10 = 9.1

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Dividing by 10: Interactive Questions

Dividing by 10: Interactive Questions

Dividing by 10 Worksheets and Answers

How to Divide a Decimal Number by 10

To divide a number by 10 we move each digit in that number one place value column to the right.

If a number has a zero in its units column, then dividing this number by ten has the effect of removing this zero.

Dividing 30 by 10

In the example above, each digit in the number 30 has been moved one place to the right. So, 30 becomes 3.0.

If the only digit after a decimal point of a number are zero then there is no need to write these zeros or the decimal point.

Instead of writing ‘3.0’, it is better to write ‘3’.

We also know from our times tables that 30 ÷ 10 = 3.

The number 30 is an example of a number that has a ‘0’ in its units column (or a number that ends in a zero).

We can see that if the number ends in a zero then dividing it by ten has the same effect as removing this zero digit.

30 became 3.

This is a trick that will only work for numbers with a zero in the units column.

It is important to understand how dividing by 10 works because not all numbers that we divide by 10 will end in a zero in their units column.

For example:

Dividing 4 by 10

To divide 4 by 10, we move the 4 one place to the right. So, it moves from the units column into the tenths column. Because there is no longer a digit in the units column, we write in a zero.

Therefore 4 ÷ 10 = 0.4.

If there are no digits before the decimal point of a number, one zero digit it always written in the units column to show this.

It is important to make sure that when we are dividing a number with more than one significant digit that we move every digit one place to the right.

For example:

Dividing 91 by 10 to leave a decimal

To divide 91 by 10, we move both digits one place to the right. We can move them one at a time to make sure that we don’t make any mistakes.

We start by moving the 9 from the tens column into the units column. The ‘1’ will then follow, remaining to the right of the ‘9’.

We move the ‘1’ from the units column into the tenths column. Therefore 91 ÷ 10 = 9.1.

We can see that the digits of ‘9’ and ‘1’ remain in this order, with the ‘9’ directly to the left of the ‘1’.

Now we will divide a decimal number by 10. For example:

Dividing a decimal number 4.6 by 10 to get another decimal number

In this example we still follow the same place value rules. Each digit in 4.6 must move one place to the right. We start by moving the 4 from the units column into the tenths column and then the 6 will follow.

The 6 is moved from the tenths column into the hundredths column.

4.6 divided by 10 is 0.46

Remember that because there are no digits in the units column or anywhere before the decimal point, we must write a single zero digit in the units column to show this.

We follow the same rules when dividing a decimal number that is less than 1 by 10.

For example:

Dividing a decimal number 0.72 by 10 to get another decimal number

We begin by moving the 7 one place to the right, from the tenths column into the hundredths column. The 2 will then follow. It moves from the hundredths column into the thousandths column.

As there are no digits in either the units column or the tenths column, we must make sure that we write zeros in here to show that their values are zero.

Alternatively, we can move the zero from the units column into the tenths column.

And so, 0.72 ÷ 10 = 0.072.

We always leave a single zero digit in the units column before the decimal point for numbers that have no more digits remaining before the decimal point.

We also put zeros between the decimal point and the first non-zero decimal digit.

We need to be more careful when dealing with numbers where there is a zero between two other digits.

For example:

Dividing a decimal number 80.5 by 10 to get another decimal number

We must make sure that we move every digit in 80.5 one place to the right, including the zero.

We move the 8 from the tens column into the units column, we move the 0 from the units column into the tenths column and we move the 5 from the tenths column into the hundredths column.

And so, 80.5 ÷ 10 = 8.05.

We can see that there are three digits ‘8’, ‘0’ and ‘5’ in this order in the original question.

We can see that these three digits remain in this order, immediately next to each other in the answer as well.

When teaching dividing by ten, it is worth making sure that the answer is sensible by comparing it to an easier example.

In this example we know that 80 divided by 10 is 8 and so we know that when we divide 80.5 by 10, we will have an 8 in the units column as well.

The digits of ‘0’ and ‘5’ will then follow the ‘8’.

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Now try our lesson on Dividing by 100 where we learn how to divide a number by 100.

Number Bonds to 20

Number Bonds to 20

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All Number Bonds to 20 display list

Part-Part-Whole Number Bonds to 20 display poster

  • Number bonds to 20 are pairs of numbers that add to make twenty.
  • The number bonds to 20 are:
  • 1 + 19
  • 2 + 18
  • 3 + 17
  • 4 + 16
  • 5 + 15
  • 6 + 14
  • 7 + 13
  • 8 + 12
  • 9 + 11
  • 10 + 10
  • There are 10 different number bonds to 20 to learn.

what are all of the Number Bonds to 20 shown as visual aids

  • Counters or cubes can be used as a visual aid to teach number bonds.
  • There are ten pairs of number bonds to 20.
  • Number bonds to 20 are the number bonds to 10 with an extra ten added to one of the numbers.
  • To learn number bonds to 20 we can use patterns.
  • 13 + 7 is similar to 17 + 3. We just have the 1 tens digit on the other number.
  • The best way to learn the number bonds to 20 is to learn the number bonds to 10 and add 10 to one of the numbers in each pair.

Number Bonds to 20 are pairs of numbers that add to make 20.

There are ten number bonds to 20 to learn.

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Number Bonds to 20: Interactive Activity

Number Bonds to 20: Interactive Questions

Number Bonds to 20 Worksheets and Answers

Number Bonds to 20 Part Part Whole Worksheets and Answers

What are Number Bonds to 20?

Number bonds to 20 are the pairs of numbers that add together to make twenty.

There are ten number bonds to 20, which are:

  • 1 + 19
  • 2 + 18
  • 3 + 17
  • 4 + 16
  • 5 + 15
  • 6 + 14
  • 7 + 13
  • 8 + 12
  • 9 + 11
  • 10 + 10

To learn the number bonds to 20, learn the number bonds to ten and add a 10 to one of the numbers in the pair.

It helps to remember the pairs of digits that make a ten, which are 1 and 9, 2 and 8, 3 and 7, 4 and 6, 5 and 5.

Below is the full display list of the number bonds to 20.

Number Bonds to 20 List display

We can see that the order of the numbers being added does not matter.

For example: 2 + 18 and 18 + 2 are the same numbers just in a different order. When teaching number bonds to 20, it is important to point this out to children who may not otherwise consciously think of this.

It is easier to memorise the pair of numbers in the sum than memorising the two sums with the numbers in a different order. Instead of remembering both 3 + 17 and 17 + 3, just focus on remembering that 3 and 17 go together.

How to teach number Bonds to 20 by looking for patterns

We can show the number bonds to 20 with a visual aid in the form of counters or cubes. This is a useful practical activity for introducing the number bonds and showing the number size and decomposition.

Number Bonds to Twenty shown with a visual aid

teaching umber Bonds to Twenty with counters

Number bonds are typically taught to children from kindergarten to first grade (KS1). When teaching number bonds to 20, it is first important to teach the number bonds to 10. The number bonds to 20 are very similar to the number bonds to 10.

The pairs of numbers that add to make 10 are:

  • 1 and 9
  • 2 and 8
  • 3 and 7
  • 4 and 6
  • 5 and 5

This is only 5 pairs of numbers. If we remember these, then we can remember the number bonds to 20.

We simply put a ‘1’ tens digit in front of one of the numbers in each pair. This is because the number bonds to 20 are just 10 larger than the number bonds to 10.

Below we can see the number bonds to 20 compared to the number bonds to 10.

Removing the ‘1’ tens digit from the number bonds to 20, we can see that we are left with the number bonds to 10.

Number Bonds to Twenty compared to the number bonds to 10

Whilst visual aids are the best teaching tool for introducing the idea of number bonds, the best way to actually learn the number bonds to 20 is by first learning the number bonds to 10. We just add a ‘1’ tens digit to one of the numbers in the pair.

When teaching number bonds to 20, it is useful to point out the pattern of increasing and decreasing numbers.

As we increase one number by one, the number that pairs with it decreases by one.

This can help memorise and learn the number bonds to 20.

learning the number Bonds to 20 with number patterns

For example if we remember that 10 + 10 = 20, then we can increase the first number by 1 and decrease the second number by 1 to get another number bonds to 20. We get 11 + 9. We can continue to increase one number and decrease the other to get 12 + 8 and so on.

Number bonds require practise to learn and memorise. We recommend using our online number bonds to 20 activity to help learn them.

Alternatively, we have part part whole model worksheets. The part part whole teaching model is made up of three circles. The larger number goes in the largest circle and two smaller circles contain the two numbers that add to make this number.

Here are all of the number bonds to 20, shown as part part whole models.

all of the number bonds to 20 shown as part part whole teaching model

The entire list of number bonds to 20 are shown as a display poster below.

If you are teaching number bonds to 20, please feel free to download and print this list.

Part-Part-Whole teaching model display poster showing all of the number bonds to 20

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Now try our lesson on Introducing Number Bonds to 100 where we learn the pairs of numbers that add to make 100.

Dividing by 100

Dividing by 100
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Dividing by 100 Summary with 400 divided by 100

  • In this example we are dividing 400 by 100.
  • To divide a number by 100, move all digits two place value columns to the right.
  • The ‘4’ moves from the hundreds column to the units (ones) column.
  • The ‘0’ in the tens column moves to the tenths column.
  • The ‘0’ in the units column moves to the hundredths column.
  • 400 ÷ 100 = 4.00
  • If the only digits after the decimal point are zeros, then they should not be written.
  • Therefore we can write: 400 ÷ 100 = 4.
  • Dividing by 100 has the same effect of removing two ‘0’ digits only if the original number ended with two ‘0’ digits in the tens and units columns respectively.
To divide by 100, move each digit two place value columns to the right.

If the number ends in two ‘0’ digits in the tens and units columns, dividing by 100 has the same effect as removing these digits.

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Dividing by 100 Example of 527 divided by one hundred

  • To divide by 100, move all digits two place value columns to the right.
  • In this example, the digit ‘5’ moves from the hundreds column into the units column.
  • The digit ‘2’ moves from the tens column into the tenths column.
  • The digit ‘7’ moves from the units column into the hundredths column.
  • 527 ÷ 100 = 5.27
  • The digits ‘5’, 2′ and 7′ remain in the same order in the answer.

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Dividing by 100: Interactive Questions

Divide a Decimal by 100: Interactive Questions

Dividing by 100 Worksheets and Answers

How to Divide a Number by 100

To divide a number by 100, move each digit in that number two place value columns to the right.

If the number ends with two zero digits in the tens and units column, then dividing by 100 has the same effect as removing these two zero digits.

This trick only works for whole numbers that are in the 100 times table (ending in two zeros).

example of dividing a number by 100. 400 divided by 100 using place value columns.

In the example above, we have 400 ÷ 100 = 4.

To divide a number by 100, move all of its digits two place value columns to the right.

The digit of ‘4’ moves from the hundreds column to the units column.

The digit of ‘0’ in the tens column moves to the tenths column, immediately after the decimal point.

The digit of ‘0’ in the units column moves to the hundredths column.

400 ÷ 100 is 4.00.

If a number only has zeros after its decimal point, then it is a whole number and there is no need to write these zeros.

It is better to write: 400 ÷ 100 = 4.

It can bee seen that we have simply “removed the two zeros”.

This trick only works for whole numbers that actually have two zeros in the tens an units columns to remove.

It is important to understand how dividing any number by 100 works because not all numbers that we divide by 100 will end in two zeros.

For example:

dividing a number 527 by 100 to get a decimal number

To divide 527 by 100, we move each digit in 527 two places to the right.

We start by moving the ‘5’ from the hundreds column two places along into the units column.

The ‘2’ and the ‘7’ will then follow the ‘5’.

The 2 moves from the tens column into the tenths column and the 7 moves from the units column into the hundredths column.

Each digit has moved two places to the right and therefore 527 ÷ 100 = 5.27.

If the number’s largest digit is in the hundreds column, then this digit will move to the units column when it is divided by 100.

The remaining digits to the right will then appear in the same order to the right of the decimal point.

So in this example, the ‘5’ is the digit to the left of the decimal point and then the ‘2’ and the ‘7’ will be in the same order, immediately after the decimal point.

In the following example we are given a number that is less than 100 and has only two digits. We still follow the same rules for dividing by 100 and move each digit two places to the right.

dividing a number, 19 by 100 to get a decimal number

We begin by moving the ‘1’ two places to the right, from the tens column into the tenths column. The ‘9’ will then follow. We move it from the units column into the hundredths column.

Whenever there are no digits remaining to the left of the decimal point, a single ‘0’ digit is written in the units column.

Therefore, 19 ÷ 100 = 0.19.

We may be asked to divide a single-digit number by 100.

For example:

dividing a number, 6 by 100 to get a decimal number

Although 6 has only one digit, we still follow the same rule for dividing by 100. We move the 6 two places to the right. It moves from the units column into the tenths column.

Because there is no longer a digit in the units column and there is a space in the tenths column, we write a zero in both columns to show that their values are zero.

Therefore 6 ÷ 100 = 0.06.

We need to be careful when dealing with numbers where there is a zero between two other non-zero digits.

For example:

dividing a decimal number by 100 to get another decimal number

To divide by 100, we must make sure that we move every digit in 30.2 two places to the right, including the zero. We move the 3 from the tens column into the tenths column, we move the zero from the units column into the hundredths column and we move the 2 from the tenths column into the thousandths column.

The digits remain in the same order. And so, 30.2 ÷ 100 = 0.302.

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Now try our lesson on Dividing by 1000 where we learn how to divide a number by 1000, with examples and further practice.

Number Bonds to 10

Number Bonds to 10

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number bonds to 10 poster

  • Number bonds to 10 are pairs of numbers that add to make ten.
  • The number bonds to ten are:
  • 1 + 9.
  • 2 + 8.
  • 3 + 7.
  • 4 + 6
  • and 5 + 5

Teaching the number Bonds to 10 poster

  • Number bonds are important for providing a visual understanding of the size of a number.
  • Number bonds help with understanding addition and subtraction.
  • Number bonds help to show that there are many ways in which one number can be formed or broken down.
  • When teaching number bonds to 10, remember that there are only 5 separate pairs of numbers to learn.
  • Remembering one number bond pair can help to learn the rest.
  • For example, starting with 5 + 5, we can increase one number and decrease the other to form 6 + 4.

Number Bonds to 10 are pairs of numbers that add to make 10.

There are 5 pairs of numbers to learn.

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Number Bonds to 10: Interactive Activity

Number Bonds to 10: Interactive Questions

Teaching Number Bonds to 10 Worksheets and Answers

Number Bonds to 10 Part Part Whole Worksheets and Answers

Number Bonds to 10 Tens Frame Worksheets and Answers

What are Number Bonds to 10?

Number bonds to 10 are pairs of numbers that add together to equal 10.

The poster below shows the complete list of number bonds to 10.

what are the number bonds to 10 poster

Number bonds to 10 are usually one of the first set of number facts that are taught.

Number Bonds to 10 are usually taught to primary school children in their first or second year (KS1 or First Grade).

Number bonds are important for developing further skills such as addition and subtraction. Learning number bonds to 10 then lead on to learning number bonds to 20 and further number facts up to 100. Number bonds also help children to visualise the size of numbers.

It is important to teach number bonds to 10 visually, with practical activities when first introducing them. This can be done with counters as shown below.

Number Bonds to Ten counting using counters

Tens frames can be used as a guide to put the counters in. Tens frames are simple blank rectangles that are 2 by 5 in size.

blank tens frame for the number bonds to 10

To use a tens frame, simply shade in some of the boxes (or put counters in) and then see how many more filled boxes are required to fill the complete frame of 10.

For example, here is a tens frame already containing 2 counters.

It is used to work out which number bond pairs with 2 to make 10.

To use a tens frame, add a counter to each blank box and then count how many counters have been added.

number bond to 10 tens frame with 2

8 more counters are needed to fill the frame.

full tens frame 10

When introducing the idea of number bonds, further practical activities can be used, such as multi-link cubes or dominoes.

It can help to give time to practise with physical models in order to develop a good understanding of how the number 10 can be broken down into different sums.

However to memorise number bonds to 10, we can see that there are only five pairs of numbers to remember.

Number Bonds to Ten pairs of numbers that add to make 10

The pairs of numbers that add to make 10 are:

  • 1 and 9
  • 2 and 8
  • 3 and 7
  • 4 and 6
  • 5 and 5

numicon number bonds to 10 in a tens frame layout

Remembering 5 pairs of numbers is easier than remembering 10 separate addition facts.

For example: 1 + 9 contains the same pair of numbers as the number bond of 9 + 1.

We simply swap the positions of the two numbers.

When teaching number bonds to 10, it is useful to break it down into the task of remembering the 5 pairs of numbers that add to make 10.

If you remember one of the number bonds to 10, then you can use this to work out some of the others.

The pairs of numbers that add to make 10 are shown again below and we can see a pattern with the numbers.

As the first number increases from 1 to 5, the second number decreases from 9 to 5.

  • 1 and 9
  • 2 and 8
  • 3 and 7
  • 4 and 6
  • 5 and 5

We can get to another number bond by adding 1 to one of the numbers and subtracting one from the other number.

For example if we remember 5 + 5 , then we can add 1 to one number and subtract 1 from the other to make 6 + 4.

If we remember 1 + 9, we can add 1 to the first number and subtract 1 from the second number to make 2 + 8.

In order to move swiftly on to learning the number bonds to 20 and further addition facts, it is important to know the number bonds to 10 with quick recall.

Part, part whole models are often used for practising number bonds to 10.

Part, part whole models contain 3 circles with a larger circle connected to two smaller circles.

The larger circle contains the number bond we are making, which in this case is 10.

One of the smaller circles contains one part of the number bond and the other smaller circle is blank, ready to be filled in.

Part-Part-Whole model for learning Number Bonds to 10

We have part part whole model worksheets for download with which you can practise this.

Here are the complete set of number bonds to 10 shown with the part part whole model.

Part part whole model for the Number Bonds to 10

Games, competitions and quick tests are very useful ways to practise and we have Interactive Questions that you can use.

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Now try our lesson on Number Bonds to 20 where we learn the pairs of numbers that add to make 20.

Column Subtraction Borrowing from Zero

Column Subtraction Borrowing from Zero
summary

summary

  • In the column subtraction of 405 – 297 we need to borrow from the tens column since 7 is greater than 5.
  • However we have a zero in the tens column.
  • We first borrow a hundred from the ‘4’ in the hundreds column and regroup it to the tens column to make the ‘0’ into a ’10’.
  • We can now borrow from this ’10’ in the tens column and carry a one into the units column to make ’15’.
  • We can now subtract all columns because the numbers we are subtracting from are now all larger.

Alternate Method

alternatemethod

We can treat the ‘400’ as ’40’ tens’ and borrow a ten immediately to leave ’39’ tens in total.

Download our printable workbooks for further practice of column subtraction.

Column Subtraction

Column Subtraction Borrowing From Zero

In this lesson we will be learning how to use the column subtraction method when we need to borrow from zero. These examples will be of column subtraction with zero in the middle of a three digit number.

We will look at how to calculate 604 – 328. Here we are subtracting from a three-digit number with zero in the middle.

604 – 328 set out as column subtraction

We begin by lining up the digits in their place value columns. We want to subtract the digits in the units column. However, 8 is greater than 4, so we can’t.

We would normally borrow (regroup) from the tens column. However, we have a zero written here, which means that there aren’t any tens.

604 – 328 set out as column subtraction

Therefore, before we can borrow some units from the tens, we need to borrow some tens from the hundreds column. We need to borrow from the 6 hundreds.

604 – 328 set out as column subtraction borrowing from the hundreds column

We move 1 hundred next to the zero to make 10 tens. We are left with 5 hundreds. This process is also known as regrouping.

604 – 328 set out as column subtraction borrowing from the hundreds and tens columns

Now that we have 10 tens, we can borrow some units from this column. We move 1 ten next to the 4 to make 14 units. We are now left with 9 tens in the tens column.

604 – 328 set out as column subtraction borrowing and now subtracting the units

Now we can subtract the units.

14 – 8 = 6

Next, we subtract the tens.

604 – 328 set out as column subtraction borrowing and now subtracting the tens

9 – 2 = 7

Finally, we subtract the hundreds.

604 – 328 = 276 set out as column subtraction

5 – 3 = 2

This is the process of three-digit subtraction borrowing from zero and the result is:

604 – 328 = 276.

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Now try our lesson on Column Subtraction of Decimals with Borrowing / Regrouping where we learn how to use our knowledge of borrowing / regrouping to help us subtract decimal numbers.

Column Subtraction of Three-Digit Numbers with Borrowing Twice

Column Subtraction: Video Lesson – Maths with Mum

Supporting Lessons

Column Subtraction with Borrowing Twice: Worksheets and Answers

Column Subtraction Borrowing Twice: Random Question Generator

Column Subtraction Mixed Practice: Random Question Generator

Download our printable workbooks for further practice of column subtraction!

Column Subtraction

How to do column subtraction when we borrow twice?

We will look at how to calculate 346 – 178.

346 – 178 shown as a column subtraction

We begin by lining up the digits of each number in their place value columns. We start with the units column.

We want to subtract 8 from 6. However, 8 is greater than 6, so we can’t take it away.

346 – 178 shown as a column subtraction

We must therefore borrow some units from the tens column. We can borrow from the 4 tens.

346 – 178 shown as a column subtraction borrowing from the tens column

We move 1 ten next to the 6. We have 16 units in total. We are left with 3 tens in the tens column.

346 – 178 shown as a column subtraction subtracting the units having borrowed from the tens

We can now subtract the units.

16 – 8 = 8

Next, we look at the tens column.

346 – 178 shown as a column subtraction subtracting the units having borrowed from the tens

We want to subtract the 7 from the 3. However, 7 is greater than 3, so we can’t.

346 – 178 shown as a column subtraction subtracting the units having borrowed from the tens

We must therefore borrow from the hundreds column. We can borrow from the 3 hundreds.

346 – 178 shown as a column subtraction subtraction borrowing from the hundreds

We move 1 hundred next to the 3 in the tens column. This makes 13 in the tens column. We are left with 2 hundreds in the hundreds column.

346 – 178 shown as a column subtraction subtraction borrowing from the hundreds

We can now subtract the tens.

13 – 7 = 6

Finally, we look at the hundreds column.

346 – 178 =168 shown as a column subtraction subtraction borrowing from the hundreds

Because we borrowed 1 hundred, we are left with 2 hundreds.

2 – 1 = 1

Therefore,

346 – 178 = 168.

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3-Digit Column Subtraction with Borrowing / Regrouping

3-Digit Column Subtraction with Borrowing / Regrouping – Maths with Mum

Supporting Lessons

Column Subtraction with Borrowing / Regrouping: Worksheets and Answers

Column Subtraction with Borrowing / Regrouping: Interactive Questions

Download our printable workbooks for further practice of column subtraction with Borrowing / Regrouping!

Column Subtraction

How to do Column Subtraction with Borrowing / Regrouping

In order to calculate the column subtraction of 592 – 226, we must begin by lining up the numbers so that their digits are in the correct place value columns.

We want to subtract 226, so this must be written below 592.

592 - 226 shown as a column subtraction

We begin with the units column. However, the 6 is larger than the 2, so we can’t subtract it without regrouping.

592 - 226 shown as a column subtraction looking at the tens for borrowing regrouping

We must therefore borrow some units from the tens column. We can borrow from the 9 tens.

592 - 226 shown as a column subtraction borrowing from the tens

We regroup 1 ten to borrow and we carry it over into the units column, next to the 2. In total, we now have 12 units. This leaves us with 8 tens in the tens column.

592 - 226 shown as a column subtraction borrowing regrouping from the tens column

Following this regrouping, we can now subtract the units.

12 – 6 = 6

Next, we look at the tens column.

592 - 226 shown as a column subtraction involving borrowing regrouping

Because we borrowed from the 9, we are now left with 8 tens.

8 – 2 = 6

Finally, we look at the hundreds column.

592 - 226 = 366 shown as a column subtraction with borrowing

5 – 2 = 3

Therefore,

592 – 226 = 366.

Another column subtraction example that we will look at is 674 – 482.

674 – 482 shown as column subtraction looking at the units

Again, we line up the digits of each number according to their place value columns. We start by subtracting the digits in the units column.

4 – 2 = 2

Next, we look at the tens column.

674 – 482 shown as column subtraction borrowing from the hundreds

The 8 is larger than the 7, so we can’t take it away without regrouping. We must therefore borrow from the 6 in the hundreds column.

674 – 482 shown as column subtraction borrowing regrouping from the hundreds

We regroup 1 hundred for the tens column and write it next to the 7. This gives us 17 in the tens column. We are left with 5 in the hundreds column.

674 – 482 shown as column subtraction borrowing regrouping from the hundreds

Following this borrowing, we can now subtract the tens column.

17 – 8 = 9

Finally, we look at the hundreds column.

674 – 482 = 192 shown as column subtraction with borrowing regrouping

Because we borrowed from the 6, we are now left with 5 hundreds.

5 – 4 = 1

Therefore,

674 – 482 = 192.

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How to Write Percentages as Decimals

How to Write Percentages as Decimals

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example of writing 50% as decimal number

  • The percent symbol is %.
  • Per means ‘divide by’ and cent means ‘100’.
  • To convert from a percent to a decimal, we divide the number by 100.
  • 50 divided by 100 is 0.5.
  • 50% written as a decimal number is 0.5.
  • We do not write the percentage sign after our answer now that we have divided by 100.
  • 50% is the same as one half. 0.5 is how we write one half as a decimal.
To write a percent as a decimal, remove the % sign and divide by 100.

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example of writing 92 percent as a decimal 0.92

  • To write 92% as a decimal, we remove the % sign and divide it by 100.
  • Removing the percentage sign, we have 92.
  • To divide by 100, simply move the decimal point from the end of the number to the left by 2 places.
  • The decimal point moves from 92. to .92 when we divide by 100.
  • We write a zero in front of the decimal point to get 0.92.
  • 92% written as a decimal is 0.92.

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Supporting Lessons

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Converting Percents to Decimals: Interactive Activity

Converting Percents to Decimals: Interactive Activity

Percentage to Decimal Worksheets and Answers

Writing Percentages as Decimals

How to Convert a Percent to a Decimal

To convert a percent to a decimal, remove the percentage symbol and divide the number by 100. To divide by 100, move the decimal point 2 places to the left. For example, 92% as a decimal is 0.92.

Percent means to divide by 100.

This is because the word ‘per’ can mean ‘divide by’ and the word ‘cent’ means ‘100’. The percent symbol ‘%’ can mean ‘divide by 100’.

Here is an example of writing a percentage in decimal form. 92%, can be read to mean 92 ‘divided by 100’.

To divide a number by 100, we divide by 10 and then divide by 10 again.

dividing 92% by 100 to write it in decimal form

When a number is divided by 10, the digits move one place value column to the right.

92 ÷ 10 = 9.2. We divide by 10 again.

9.2 ÷ 10 = 0.92. We write the 0 in front of the decimal point because there are no more digits. There is not a digit to put in the ones column, so we put a 0 to show this.

Dividing a number by 100 is the same as dividing it by 10 and then by 10 again.

When dividing a number by 100, the digits each moved 2 places right.

Rather than moving each of the digits, it is easier to move the decimal point the other way instead.

To divide by 100, simply move the decimal point to the left two places.

writing 92% as a decimal number

When teaching converting percents to decimals, it is easier to divide by 100 by moving the decimal point two places left instead of moving all of the digits two places right. Students are less likely to make a mistake if they only have the decimal point to move rather than every single digit. We can leave all the digits where they are and just focus on carefully moving the decimal point two places left.

92% written in decimal form is 0.92.

Here is another example of writing a percent in decimal form.

We will write 6% as a decimal number by removing the % sign and dividing by 100.

To divide by 100, move each digit two places to the right.

example of converting 6 percent into a decimal number

6 ÷ 10 = 0.6 and then 0.6 ÷ 10 = 0.06.

6 ÷ 100 = 0.06 and so, 6% as a decimal is 0.06.

Alternatively, we can divide 6 by 100 by moving the decimal point two places left.

writing 6% as a decimal

The decimal point must move twice.

We move the decimal point once to go from 6. to .6 and now we need to move it once more.

We need to put a 0 in front of the 6 digit so that we can jump over that.

We go from 0.6 to .06 and we write a zero in front of the decimal point to get 0.06.

6 ÷ 100 = 0.06 and so 6% as a decimal is 0.06.

It is important to move the decimal point carefully when converting a percentage to a decimal.

It is a common mistake to write percentages such as 6% as 0.6 instead of 0.06. It is common to miss out the extra 0 after the decimal point.

When converting a single digit percentage to a decimal, there will always be a 0 between the decimal point and the digit. In general a% can be written as a decimal as 0.0a.

For example, 5% is 0.05, 3% is 0.03 and 9% is 0.09.

To converting a double digit percentage to a decimal, simply write the two digits immediately after the decimal point. In general ab% can be written as a decimal as 0.ab.

For example, 25% is 0.25, 37% is 0.37 and 99% is 0.99.

Converting a Decimal Percentage to a Decimal

No matter what the percentage is, divide it by 100 to write it as a decimal number. If the percentage is already a decimal number, then when it is written as a decimal, it will be 100 times smaller. For example 3.2% as a decimal is 0.032.

It is possible to have decimal percentages. For example 3.2%.

The rule remains the same. Remove the % sign and divide the number by 100.

The decimal percentage 3.2% written as a decimal

To divide by 100, we divide by 10 twice.

3.2 ÷ 10 = 0.32 and then 0.32 ÷ 10 = 0.032.

3.2% is 0.032 as a decimal. Because the % sign has been removed, the number has now got 100 times smaller.

It can be easier to move the decimal point two places to the left.

converting 3.2% to decimal form

Moving the decimal point two places we go from 3.2 to 0.32 to 0.032.

3.2% is 0.032.

Here are some examples of converting percentages to decimals.

Percentage Decimal
48% 0.48
2% 0.02
0.6% 0.006
2.57% 0.0257
200% 2
354% 3.54

Simply divide the percentage by 100 to get it in decimal form.

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Now try our lesson on Converting Decimals to Percentages where we learn how to write a decimal as a percentage.

Divisibility by 2, 5 and 10

Divisibility by 2, 5 and 10

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Rule for Divisibility by 2

rule for divisibility by 2

Rule for Divisibility by 5

rule for divisibility by 5

Rule for Divisibility by 10

rule for divisibility by 10

  • If a number is divisible by 2, it means that it is in the 2 times table.
  • If a number is divisible by 5 or 10, it means that it is in either the 5 or 10 times table respectively.
  • To check if a number is divisible by 2, 5 and 10, look at its final digit.
  • A number is divisible by 2 if it ends in 2, 4, 6, 8 or 0.
  • A number is divisible by 5 if it ends in 5 or 0.
  • A number is divisible by 10 if it ends in a 0.
To test for divisibility by 2, 5 or 10, look at the final digit of the number.

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checking if 6730 is divisible by 2, 5 or 10

  • The last digit of the number 6730 is 0.
  • A number is divisible by 2 if it ends in 2, 4, 6, 8 or 0.
  • The number ends in a 0 and so it is divisible by 2.
  • A number is divisible by 5 if it ends in 5 or 0.
  • The number ends in a 0 and so it is divisible by 5.
  • A number is divisible by 10 if it ends in a 0.
  • The number ends in a 0 and so it is divisible by 10.
  • A number that ends in 0 is divisible by 2, 5 and 10.
  • 6730 is divisible by 2, 5 and 10, which means that it is in the 2, 5 and 10 times table.

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Divisibility by 2, 5 and 10: Interactive Questions

Divisibility by 2, 5 and 10: Interactive Questions

Divisibility by 2, 5 and 10 Worksheets and Answers

Divsibility by 2, 5 and 10

How to Check Divisibility by 2, 5 or 10

To check if a number is divisible by 2, 5 or 10, follow these steps:

  • Look at the last digit of the number.
  • If the digit is a 2, 4, 6, 8 or 0, the number is divisible by 2.
  • If the digit is a 5 or a 0, the number is divisible by 5.
  • If the digit is a 0, the number is divisible by 10.

For example, here is 68. We will check if it is divisible by 2, 5 or 10.

Its last digit is 8.

If the digit is a 2, 4, 6, 8 or 0, the number is divisible by 2. Therefore 68 is divisible by 2.

checking if 68 is divisible by 2

The last digit must be a 5 or a 0 for the number to be divisible by 5. 8 is neither of these digits and so, 68 is not divisible by 5. It is not in the 5 times table. A number can be divisible by 2, 5 and 10. If a number is divisible by 10, it is also divisible by 2 and 5.

For example, here is 70.

checking a number of 70 using the rule for divisibility by 10

70 ends with a digit of 0.

A number must end in a 0 to be divisible by 10. 70 is in the 10 times table. It is divisible by 10.

If the digit is a 2, 4, 6, 8 or 0, the number is divisible by 2. Since 70 has a final digit of 0, it is divisible by 2.

A number must end in a 5 or a 0 to be divisible by 5. 70 ends in a 0 and so, it is divisible by 5 too.

A number divisible by 10 is also divisible by 2 and 5 because 2 and 5 both divide into 10.

Which of the Following Numbers are Divisible by 2, 5 or 10?

If a number ends in 2, 4, 6, 8 or 0, it is divisible by 2. If it ends in 5 or 0, it is divisible by 5. If it ends in 0, it is divisible by 10. If it is divisible by 10, it is also divisible by 2 and 5.

Here is a table of examples of numbers that will be checked for divisibility by 2, 5 and 10 using this rule.

Number Last Digit Divisible by 2 Divisible by 5 Divisible by 10
42 2
25 5
80 0
1908 8
7540 0
3895 5

42 ends in a 2 and so, it is divisible by 2 but not 5 or 10.

25 ends in a 5 and so, it is divisible by 5 but not 2 or 10.

80 ends in a 0 and so, it is divisible by 2, 5 and 10.

1908 ends in an 8 and so, it is divisible by 2 but not 5 or 10.

7540 ends in a 0 and so, it is divisible by 2, 5 and 10.

3895 ends in a 5 and so, it is divisible by 5 but not 2 or 10.

Rule for Divisibilty by 2

A number is divisible by 2 only if its last digit is a 2, 4, 6, 8 or 0. For example, 426 is divisible by 2 because it ends in a 2. 327 is not divisible by 2 because it ends in a 7.

If a number is divisible by 2, it means that is can be divided by 2 exactly without a remainder. It is in the 2 times table.

All numbers in the 2 times table repeat the pattern of the last digit ending in 2, 4, 6, 8 and 0.

why does the rule for divisibility by 2 work?

Every time we get to a number ending in 0, the pattern starts again.

This means that to check if a number is a multiple of 2, simply look at the last digit and ignore all preceding digits. If the number ends in 2, 4, 6, 8 or 0, the number is a multiple of 2.

For example, we will use the rule to test if 68 is divisible by 2.

using the rule to check if 68 is divisible by 2

68 ends in an 8, which is one of the digits 2, 4, 6, 8 or 0.

68 is divisible by 2 because it is an even number.

It does not matter how large the number is, only look at the last digit to decide if a number is divisible by 2. For example, here is 37,110.

testing larger number of 37110 to see if it is divisible by 2

37,100 ends in a 0. 0 is an even number and so, 37,100 is divisible by 2.

Here is 209, which ends in a 9.

a number 209 that is not divisible by 2

A number must end in 2, 4, 6, 8 or 0 to be divisible by 2. If a number ends in 9 it is not divisible by 2.

209 is not divisible by 2.

Rule for Divisibilty by 5

A number is divisible by 5 only if its last digit is a 5 or a 0. For example, 935 is divisible by 5 because it ends in a 5. 732 is not divisible by 5 because it ends in a 2.

If a number is divisible by 5, this means it can be divided exactly by 5 with no remainder. It is in the 5 times table.

All numbers in the 5 times table repeat the pattern of ending in 5 or 0.

why does the divisibility by 5 rule work?

If a number ends in any other digit apart from 5 or 0, it is not in the 5 times table.

For example, here is 45.

testing if 45 is divisible by 5

45 ends in a 5. Numbers that end in 5 or 0 are divisible by 5 and so, 45 is divisible by 5.

It does not matter how large a number is. If a number ends in a 5 or a 0, it is in the 5 times table. We only need to look at the last digit.

Here is 17,760.

testing a larger number to decide if it is a multiple of 5

17,760 ends in a 0. If a number ends in a 5 or a 0, it is divisible by 5.

Therefore 17,760 is divisible by 5.

Here is 803.

example of a number that is not divisible by 5

803 ends in a 3. To be divisible by 5, a number can only end in a 5 or a 0.

803 is not divisible by 5.

Rule for Divisibilty by 10

A number is divisible by 10 only if it ends in a 0. For example, 770 is divisible by 10 because it ends in a 0. 565 is not divisible by 10 because it ends in a 5.

If a number is divisible by 10, this means that is can be divided exactly by 10 with no remainder. It is in the 10 times table.

All numbers in the 10 times table end in a 0.

If a number does not end in a 0, it is not in the 10 times table.

why does the rule for divisibility by 10 work?

For example, here is 70.

70 is in the ten times table

70 ends in a 0. If a number ends in a 0, it is in the 10 times table and can be divided exactly by 10.

70 is divisible by 10.

It does not matter how large a number is, if it ends in a 0, it is divisible by 10.

For example, here is 2,070,420.

example of a large number that is divisible by 10

2,070,420 ends in a 0. We do not need to look at the digits in front of the last digit to decide.

2,070,420 is divisible by 10 because it ends in a 0.

Here is the example of 177.

example of a number that is not divisible by 10

177 ends in a 7. For a number to be divisible by 10, it must end in a 0.

177 is not divisible by 10.

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Now try our lesson on Divisibility by Four where we learn how to check if a number is divisible by 4.

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