Written subtraction
Practise careful regrouping so that subtraction such as 40,000 - 18,537 stays readable and checkable.
How to solve this
- Line up the columns before subtracting; the smaller number may have fewer digits but its ones still go under ones.
- If a column cannot be subtracted, regroup from the next available place. Across zeroes, move left until a non-zero digit can lend.
- Check subtraction by addition: if 40,000 - 18,537 = 21,463, then 21,463 + 18,537 must be 40,000.
Examples
7,305 - 2,846
4,459
40,000 - 18,537
21,463
9,002 - 4,875
4,127