Definition
Regrouping is the process of rearranging numbers by place value when adding or subtracting. You trade between ones, tens, hundreds, and so on.
Regrouping is like exchanging coins. You trade 10 pennies for 1 dime, or break 1 dime into 10 pennies, depending on whether you are adding or subtracting.
Examples
- When adding 27 + 15, the ones column gives 12, so you regroup 10 ones as 1 ten.
- When subtracting 43 - 18, you regroup 1 ten into 10 ones.
- 56 + 47 = 103 requires regrouping from ones to tens and from tens to hundreds.