This week in math, we are learning how to break apart numbers to subtract. To assist my students in doing this, I’ve uploaded a “120 chart” on my website. Students may use this as a visual aide to assist them with doing breaking apart numbers to subtract and, eventually, my hope is that students will be able to visualize this chart in their head, so that they may solve problems that may seem complicated using only “mental math”.
Using the 120 chart to solve a problem like “50 – 37 = ?” my students are expected to know how to:
Break apart 37 into 7 ones and 3 tens
Find 50 on the hundred chart and point to it
“Jump back” 3 tens and 7 ones
Land on the number 13, which is the correct answer to the problem “50 – 37 = ?”
At this time in our second grade classroom, we are focusing on the following addition strategies:
Solving word problems by finding the given information, determining what the problem is asking us to find, and identifying key words or phrases
Solving addition problems with up to 4 addends vertically
While there are number of strategies my students know how to use, I’m a big fan of the “spiral review”, which includes going back and reminding ourselves of some addition tips and tricks we may have picked up in first grade. I recently discovered fun educational hip hop videos created by Flocabulary, a Brooklyn-based company that creates educational hip hop songs and videos for students in grades K through 12. Below is a video that we watched on Monday to remind us of our “tens partners” which will help us add (and subtract… which we will be delving into when we return from the winter break in January) more quickly!