As we already learned, we can get new place value additions by regrouping (borrowing) the tens and ones in two-digit whole numbers. This is very useful for subtraction problems that require regrouping.
Let's take 82 as an example. What is the place value addition for 82?
The place value addition is 80 plus 2. But 82 can have another place value addition. How can we find it? Do you have a guess? If you said regrouping, you're right!
Let's borrow 1 ten from the digit in the tens place (tens column), which is 8. Cross out the digit and replace it with the digit that is one less than the original number, giving you 7.
Next, let's place the 1 ten we regrouped from 8 and write it small in front of the digit in the ones place (ones column), 2.
Now let's use our new digits! The new digit in the tens column is 7; 7 tens equal 70. The small 1 beside the 2 shows us that we need to add 10 to the 2: 10 plus 2 equals 12 (10 + 2 = 12). So what do we have?
We now have a new place value addition for 82: 70 plus 12.
