- Here is a 100 number grid arranged in rows of 10.
- To add one to a number, we move one place to the right.
- For example, 15 + 1 = 16.
- To subtract one from a number we move one place to the left.
- For example 85 – 1 = 84.

**We move right when adding and we move left when subtracting.**

#### Printable Number Grid 1-100

- Every time we add 1, we move one place to the right on our number grid.
- When we reach the end of a rowHere each row is a line of numbers that goes across from left to right., to add one more, we start at the beginning of the next row.
- 38 + 4 means that we find 38 and move to the right 4 places.
- We move one place to the right to get to 39.
- We move a second place to the right to get to 40.
- We are now at the end of the row so to add one a third time we start at the beginning of the next row at 41.
- We add one a fourth time to get to 42.
- We have added 4 in total by moving 4 places.
- 38 + 4 = 42.

#### Adding and Subtracting Single Digit Numbers Worksheets and Answers

# How do we Add or Subtract Single-Digit Numbers using a 100 Number Grid?

**add 1**to a number using the number grid, we move one place to the

**right**and when we

**subtract 1**from a number, we move one place to the

**left**.

In this lesson, we will look at adding and subtracting multiples of 1 using the number grid.

Above are the first nine multiples of 1.

We can see that:

**1** is **1** lot of 1

**2** is **2**lots of 1

**3** is **>3** lots of 1

**4** is **4** lots of 1

**5** is **5** lots of 1

**6** is **6** lots of 1

**7** is **7** lots of 1

**8** is **8** lots of 1

**9** is **9**lots of 1

This tells us how many places we move left or right on the number grid.

For example, if we are **adding 3**, we move **3** places to the **right** on the number grid, or if we are **subtracting 5**, we move **5** places to the **left** on the number grid.

Here is an example of addition using the number grid:

We are asked: what is 14 + 5?

When we **add 1**, we move 1 place to the **right** on the number grid.

5 is 5 lots of 1, so we move **5** places to the **right**.

We **start at 14** and we move **5** places to the **right** on the number grid.

We stop at 19.

Therefore,

**14 + 5 = 19**.

Here is another example of addition using the number grid:

We are asked: what is 38 + 4?

When we **add 1**, we move 1 place to the **right** on the number grid.

4 is 4 lots of 1, so we move **4** places to the **right**.

We start at **38** and want to move **4** places to the **right**.

After moving 2 places, we land on 40, which is at the **end of the row**.

So, we can’t move any further to the right.

Our next step is to move to the **beginning of the next row**.

We have now moved 3 places. We now move 1 more place to the right.

In total, we have moved 4 places.

Therefore,

**38 + 4 = 42**.

Here is an example of subtraction using the number grid:

We are asked: what is 28 – 6?

When we **subtract 1**, we move 1 place to the **left** on the number grid.

6 is 6 lots of 1, so we move **6** places to the **left**.

We start at **28** and we move **6** places to the **left** on the number grid.

We stop at 22.

Therefore,

**28 – 6 = 22**.

Here is another example of subtraction using the number grid:

We are asked: what is 91 – 8?

When we **subtract 1**, we move 1 place to the **left** on the number grid.

8 is 8 lots of 1, so we move **8** places to the **left**.

We start at **91** and want to move **8** places to the **left**.

We are starting at the **beginning of the row**, so we can’t move any further to the left.

Therefore, our first step is to move to the **end of the previous row**.

We have moved 1 place, so we now need to move 7 more places to the left.

We stop at 83.

Therefore,

**91 – 8 = 83**.

Now try our lesson *Number Grid: Adding and Subtracting Ten*, where we learn how to add and subtract ten using a 100 number grid.