Moving an amount (usually 10) from one part of a calculation to another so it is easier to do the calculation.
Example: 32 − 15
How do we subtract 5 from 2?
We "regroup" 32 (3 tens and 2 ones) into 2 tens and 12 ones
NOW we can subtract 5 from 12 and get 7
And finish up by subtracting 1 ten from 2 tens
To get our answer of 17
../numbers/images/moving-tens.js