Last week, students learned the strategies, “Use Addition to Subtract on an Open Number Line,” and “Decompose to Subtract.”  

With the strategy, “Using Addition to subtract,” students will use their knowledge of how to count on from the smaller number.  

With the strategy, “Decompose to Subtract,” students will break apart the number being subtracted to get to a decade number. Then, students will subtract the other partner number to find the difference.  

For example: 

 53 - 7 =?  

Break the 7 into a 3+4 

Subtract: 53 - 3 = 50, then 50 - 4 = 46.  

So, 53 – 7 = 46 

At the end of the week, we started to learn about the strategy of compensation. That is where we will pick up again this week. Compensation to subtract was confusing to students, so we will be spending more time on that. You can watch this video if you are interested in learning how this strategy works. 

Next, we will focus on solving 2-step word problems involving subtraction. I hope to end the week with the Chapter 5 Post-test.