Maths › Adding and taking away › Column addition and subtraction
Column addition and subtraction: line up the digits
Free printable worksheets for crossing a ten in your head, like 32 − 3, and for column adding and taking away with 2, 3 or 4 digits. Choose sums with or without exchanging. Every sheet comes with an answer page that shows the exchanges.
Crossing a ten in your head
Before column methods, it helps to be quick at sums that cross a ten, like 32 − 3 or 47 + 6. The trick is to stop at the ten on the way.
1Find the tenFor 32 − 3, the ten you pass is 30.
2Jump to it32 take away 2 gets you to 30. That uses 2 of the 3.
3Use what’s left1 more to take away: 30 − 1 = 29.
How column addition works
- Line up the digits. Ones under ones, tens under tens, hundreds under hundreds. Squared paper makes this much easier.
- Always start with the ones. Work from right to left, one column at a time.
- “Exchanging” is the same as carrying and borrowing. Ten ones swap for one ten, and one ten swaps for ten ones. Showing it with coins or counters helps it make sense.
- Estimate first. 47 + 25 is about 50 + 25, so the answer should be about 75.
Make a sheet
Choose the kind of sheet and how hard it is, then roll for a fresh one.
Tips for parents
- Say what each digit is worth. In 47, the 4 is four tens, or 40. Saying “4 tens add 2 tens” keeps the columns making sense.
- Use real things for exchanging. Swap ten 1p coins for a 10p, or bundle ten straws with a band, then unbundle them again for taking away.
- Do the “no exchanging” sheets first. When they’re easy, move to sheets with exchanging.
- Check with the opposite sum. If 52 − 27 = 25, then 25 + 27 should make 52.
In the National Curriculum for England, Year 2 children add and subtract a two-digit number and ones, and a two-digit number and tens, including mentally. In Year 3 they learn the formal written methods of column addition and subtraction for numbers with up to three digits, and in Year 4 for numbers with up to four digits.