How do you subtract three digit numbers when you need to regroup hundreds and tens'?

To subtract three-digit numbers that require regrouping, start from the rightmost digit (the units). If the digit in the top number is smaller than the one in the bottom number, borrow from the next column to the left. For example, if you need to subtract 8 from 5 in the units place, you would borrow 1 from the tens place, turning the 5 into 15 and reducing the tens place by 1. Repeat this process as needed for the tens and hundreds columns.