Math 

Before Thanksgiving break, students took the Chapter 4 Post-test and Chapter 5 Pre-test. At the end of the week, students learned to use the strategy of using an open number line to subtract two-digit numbers. The YouTube video in the previous link is a great explanation of the strategy if you are interested.  

This week, we will learn 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