- To add 10 on a number grid we move down one row.
- For example, 25 + 10 = 35, since we start at 25 and move down one row.
- To add 1 on the number grid we move right one column.
- For example, 56 + 1 = 57, since we start at 56 and move right one column.

**To add 10 we move down one row.**

**To add 1 we move right one column.**

#### Printable Number Grid 1 – 100

- We are adding the 2-digit numbers 27 and 45.
- 45 is made up of 40 + 5.
- 40 is four lots of 10 and to add 40 we move down four rows.
- 27 + 40 = 67.
- We will now add the 5 by moving to the right.
- We add 3 and get to 70. To add one more, we move to the beginning of the next row.
- We arrive at 72 having added 5.
- 27 + 45 = 72.

# How to Add 2-Digit Numbers using a Number Grid

To **add ten** using the number grid, we move **down** on row of the grid.

To **add one**, using a number grid, we move one column to the **right** on the grid.

When we get to the end of a row and want to add one, we move to the beginning of a new row.

In this lesson, we will be looking at adding 2-digit numbers using the number grid for numbers between 1 and 100.

Here is our first example of adding 2-digit numbers:

What is 15 + 34?

We’ll begin by looking at the tens column of 34.

We have 3 in the tens column. This means that we have **3 lots of 10**.

So, we **start at 15** and move **3 rows down** the number grid.

We stop at 45.

Next, we will add the units.

We have 4 in the units column of 34. This means that we have **4 lots of 1**.

Every time we add one we move one column to the right.

So, we move **4 places to the right** on the number grid.

We stop at 49.

Therefore,

**15 + 34 = 49**.

Here is another example of adding 2-digit numbers:

What is 27 + 45?

We’ll begin by looking at the tens column of 45.

We have 4 in the tens column. This means that we have **4 lots of 10**.

So, we **start at 27** and ** move 4 rows down** the number grid.

We stop at 67.

Next, we’ll look at the units column of 45. We have 5 in the units column.

This means that we have **5 lots of 1**. So, we want to move **5 places to the right** on the number grid.

After moving 3 places, we **reach the end of the row**.

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

We moved **3 places** to get to the next row, now we need to move **2 more places** to the right.

We stop at 72.

Therefore,

**27 + 45 = 72**.

Now try our lesson on *Subtracting 2-Digit Numbers on the Number Grid* where we learn how to subtract 2-digit numbers using the hundred number grid.