Subtracting four-digit numbers also works in columns. When the top digit is too small, exchange one from the next column — a hundred becomes ten tens, a thousand becomes ten hundreds.
What your child will learn
- Subtract four-digit numbers in columns
- Exchange from the next column when a digit is too small
- Find a missing number in a subtraction
- Check an answer by adding back
Exchanging
In 5,243 − 1,678 you can’t take 8 ones from 3, so exchange one ten: 4 tens become 3 tens and 3 ones become 13. Nothing has been lost — the number is just written a different way.
Example questions
Here are a few questions like the ones in the first quest. Can you solve them?
1. What is 7874 − 20?
- 7856
- 7854
- 7894
- 7852
Show answer
Answer: 7854. 7874 − 20 = 7854. Check it by adding back: 7854 + 20 = 7874.
2. What is 3397 − 390?
Show answer
Answer: 3007. 3397 − 390 = 3007. Check it by adding back: 3007 + 390 = 3397.
3. What is 3499 − 469?
- 3031
- 3030
- 3968
- 2930
Show answer
Answer: 3030. 3499 − 469 = 3030. Check it by adding back: 3030 + 469 = 3499.
Tips for grown-ups
- Check every answer by adding: the answer plus the number taken away should give the starting number.
- Talk about change from large amounts of money to practise subtracting from round thousands.