Regrouping

Task

1. What number represents the same amount as 2 tens + 7 ones?
2. What number represents the same amount as 4 tens + 0 ones?
3. What number represents the same amount as 5 tens + 12 ones?
4. What number represents the same amount as 3 hundreds + 18 tens + 5 ones?
5. What number represents the same amount as 7 hundreds + 19 tens?

IM Commentary

This task serves as a bridge between understanding place-value and using strategies based on place-value structure for addition. Place-value notation leaves a lot of information implicit. The way that the numbers are represented in this task makes this information explicit, which can help students transition to adding standard base-ten numerals.

Solution

1. 27
2. 40
3. 62
4. 485
5. 890