3rd Grade Subtracting 3-Digit Numbers Worksheet, Answer Key

Trade a ten when the top is too small

If the top digit is smaller than the bottom one, borrow from the next column. One ten becomes ten ones.

In 725 − 358, 5 is smaller than 8. Trade a ten: 15 − 8 = 7. The tens now hold 1, smaller than 5, so trade a hundred: 11 − 5 = 6. Last, 6 − 3 = 3. The answer is 367.

This is the heart of subtraction in third grade.

At the table: the zero in 910

910 − 292 is the hardest one. There are no ones to take 2 from, so your child trades a ten: 10 − 2 = 8. Then there are 0 tens, less than 9, so trade a hundred: 10 − 9 = 1. Last, 8 − 2 = 6. The answer is 618.

For a and d, check that the short number sits under the ones.

To check any answer, add it back: 618 + 292 should give 910.

Subtraction in everyday life

Work out change at the shop, or how many pages are left in a book of 312 pages after reading 145. Let your child write it in columns and do the trading.

Praise the care: "You traded every time it was needed."