An addition increases the value of one number by the value of another.

Write one number underneath the other. Make sure that the digits are in columns, with each column representing a value: hundreds, tens, units.

Start by adding the numbers in the units column. Place the units digit of the answer at the bottom of the units column, and carry forward any tens digit to the next column.

Add the numbers in the tens column, including any carried forward number from the units addition. Place the tens digit of the answer at the bottom of the tens column, and carry forward any hundreds digit to the hundreds column.

Repeat the process for the hundreds column. Repeat again, if necessary, for the thousands column.

The same process can be used to add more than two numbers at the same time.

## Example 1

Add the units: 4 + 1 = 5.  Put the answer in the units column (shown in yellow).

Add the tens: 5 + 7 = 12.  From the answer, put the 2 in the tens column (green) and place the 1 in the hundreds column below the answer line (carry 1).

Add the hundreds, including the 1 brought forward: 3 + 4 + carried 1 = 8 (blue).

 3 5 4 + 4 7 1 8 2 5 1

## Example 2

A coffee shop sold 5345 cups of coffee on Saturday and 2056 cups of coffee on Sunday. How many cups of coffee did the shop sell over the weekend?

Starting with the units:

5 + 6 = 11, which is 1 and carry 1

4 + 5 + carried 1 = 10, which is 0 and carry 1

3 + 0 + carried 1 = 4

2 + 5 = 7

 5 3 4 5 + 2 0 5 6 7 4 0 1 1 1