
- 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 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.