1/15
00:00

Learn more about this topic →

G.3 Subtract two numbers with regrouping: up to three digits

Loading questions...

Go to the practice →

Subtraction with regrouping

Subtraction with regrouping is a method used when the top digit in a column is smaller than the bottom digit. We "regroup" by borrowing from the next column to the left.

Example:
52
- 27
25
Note

Regrouping is like borrowing from your neighbor when you don't have enough. We use it when we can't subtract directly because the top number is too small.

How to regroup with two digit numbers

When subtracting two-digit numbers, regroup from the tens place to the ones place when the ones digit on top is smaller than the ones digit on bottom.

Step-by-Step Process:

Problem: 63 - 28

63
- 28
35
  1. Look at the ones column: 3 is smaller than 8, so we need to regroup
  2. Borrow 1 ten from the tens place (6 becomes 5)
  3. Add 10 ones to the ones place (3 becomes 13)
  4. Now subtract: 13 - 8 = 5
  5. Subtract the tens: 5 - 2 = 3
Note

Remember: 1 ten equals 10 ones. When we regroup, we're exchanging 1 ten for 10 ones.

Regrouping with three digit numbers

With three-digit numbers, you might need to regroup from the hundreds place to the tens place, or from the tens place to the ones place.

Example with One Regrouping:

Problem: 425 - 168

425
- 168
257
  1. Ones column: 5 is smaller than 8, regroup from tens
  2. 2 tens become 1 ten, 5 ones become 15 ones
  3. 15 - 8 = 7
  4. Tens column: 1 is smaller than 6, regroup from hundreds
  5. 4 hundreds become 3 hundreds, 1 ten becomes 11 tens
  6. 11 - 6 = 5
  7. Hundreds column: 3 - 1 = 2
Note

Sometimes you need to regroup multiple times. Work from right to left, starting with the ones column.

When zero makes regrouping tricky

When you encounter zeros in the number you're subtracting from, you may need to regroup across multiple columns.

Example with Zero:

Problem: 403 - 157

403
- 157
246
  1. Ones column: 3 is smaller than 7, but there's 0 in tens place
  2. We can't borrow from 0, so we go to the hundreds place
  3. 4 hundreds become 3 hundreds, 0 tens become 10 tens
  4. Now we can borrow from tens: 10 tens become 9 tens, 3 ones become 13 ones
  5. 13 - 7 = 6
  6. 9 - 5 = 4
  7. 3 - 1 = 2
Note

When you see a zero, look to the next column to the left that has a number you can borrow from.

Checking your work

Always check your subtraction by adding your answer to the number you subtracted. The sum should equal your original number.

Checking Process:

If 72 - 38 = 34, then 34 + 38 should equal 72

34
+ 38
72

This confirms our subtraction was correct!

Note

Checking your work helps catch mistakes and builds confidence in your regrouping skills.

Go to the practice →