Year 3 subtraction works with numbers up to three digits, including exchanging (sometimes called borrowing) when a column doesn’t have enough to subtract from.
What your child will learn
- Subtract ones, tens and hundreds from a three-digit number
- Subtract three-digit numbers using the column method
- Exchange a ten for ten ones, or a hundred for ten tens
- Check answers using addition
Exchanging
In 532 − 158 there aren’t enough ones to subtract 8 from 2. Exchange one ten for ten ones: now there are 12 ones and 2 tens. The same idea works across the hundreds.
The inverse check
If 532 − 158 = 374, then 374 + 158 should equal 532. Checking with addition is quick and catches most slips.
Example questions
Here are a few questions like the ones in the first quest. Can you solve them?
1. What is 948 − 6?
Show answer
Answer: 942. 948 − 6 = 942. Check it by adding back: 942 + 6 = 948.
2. What is 687 − 64?
Show answer
Answer: 623. Take away the tens first: 687 − 60 = 627. Then take away the ones: 627 − 4 = 623.
3. What is 353 − 1?
- 356
- 352
- 351
- 354
Show answer
Answer: 352. 353 − 1 = 352. Check it by adding back: 352 + 1 = 353.
Tips for grown-ups
- Work out how many pages are left in a book.
- Use money to model exchanging: swap one note for ten smaller coins, just like one ten becomes ten ones.