The idea
Column subtraction keeps equal place values aligned and exchanges when necessary.
Follow these steps
- Align the digits by place value.
- Subtract from right to left, exchanging from the next column where needed.
- Check with the inverse addition.
See the method in action
Example 1
How much greater is 7,068 than 2,871?
- Regroup across the zero before subtracting each aligned column; the difference is 4,197.
Example 2
A project budget is £12290. Equipment costs £2889 and materials cost £1921. How much remains?
- First add the costs: 2889 + 1921 = 4810.
- Then subtract: 12290 − 4810 = 7480.
A useful shortcut
Check with the inverse addition.
Watch out for these
Three fresh questions
Ready to check the method? You will get three fresh, validated questions.