**Part 1**: Follow along with your instructor. Find the difference by “taking away”

**Part 2**: Follow along with your instructor. Find the difference by “taking away”. This problem regroups twice. To take away 173:

- Start by taking away 3 ones.
- Then, take away 7 tens. Since there are not enough tens to take away, regroup. Take a hundreds flat and physically break it apart into tens. Now you have enough tens to take away 7 of them.
- Finally, take away 1 hundred.

**Part 3**: Subtract. Some of these problems require regrouping.