## Tuesday, May 20, 2014

### Subtraction with Regrouping

Subtraction with regrouping is one of the hardest concepts for our students to grasp. They get so mixed up and try to regroup like they did in addition. Does anyone else have this problem??? We knew we needed to do something to help them understand why and how we regroup in subtraction!

We teach our kids 4 strategies. We start with base ten blocks. We have them work with a partner to practice different problems. They build the numbers and manipulate the blocks to come up with the answer. We also have them write about the problem and explain the steps they do in order to solve it. We've learned that this is the best way to start our unit!

After they have a handle on the base ten blocks. We move to the open number line.  This is the easiest strategies for students.

The next strategy we work on is decomposing, we won't lie.... this is the most challenging. I kind of dread this one! BUT it's so important.

Finally, we get to the algorithm.  The kids think they are so cool when they finally learn this! They think they are "big kids."  After all the strategies they truly have a deeper understanding of subtraction with regrouping.

We made some worksheets that require the student to complete all 4 strategies with the same problem. You can grab one of them here!

We will be finishing up our subtraction unit this week!

-Sister 3-