How to set out an addition
Write the numbers one under the other, neatly aligned to the right: units under units, tens under tens. Put the + sign on the left, draw a line, then add column by column, starting from the units.
Addition without carrying
When each column adds up to less than 10, there is no carry. Example: 324 + 251.
324 + 251 = 575
Units: 4 + 1 = 5. Tens: 2 + 5 = 7. Hundreds: 3 + 2 = 5. You read 575.
Addition with carrying
When a column is more than 9, you write the units digit and carry 1 over to the next column: that is the carry. Example: 358 + 476.
358 + 476 = 834 — the carries 1 are carried to the left
- Units: 8 + 6 = 14. Write 4 and carry 1.
- Tens: 5 + 7 = 12, + the carry 1 = 13. Write 3 and carry 1.
- Hundreds: 3 + 4 = 7, + the carry 1 = 8. Write 8. Result: 834.
Mistakes to avoid
- Misaligning the numbers: always line up the units on the right.
- Forgetting the carry at the next column.
- For numbers of different sizes (e.g. 45 + 8), remember that 8 is a number of units: it goes under the 5.
Worked exercises
241 + 135
67 + 28
486 + 259
Now it's your turn!
On EasyMaths, your child practises column addition with exercises that never repeat and instant marking. The first exercises are free.
Start the exercises →Frequently asked questions
How do you set out an addition?
Write the numbers one under the other, aligned to the right (units under units). Draw a line, then add each column starting with the units.
What is a carry?
When the sum of a column is more than 9, you write the units digit and carry 1 over to the next column, on the left.
At what age do children learn column addition?
From around age 6, then carrying is consolidated around ages 7 to 9.