Using Scales to Model Solving Equations with Variables on Both Sides

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1 Updated Version of Types of Solutions Foldable

2 Free Downloads for Solving Equations with Variables on Both Sides

3 More Resources for Teaching Solving Equations

I used Sarah Rubin’s idea of using scales to model solving equations with variables on both sides. It turned out to be a brilliant introduction to the concepts of one solution, no solution, and infinite solutions.

solving equations with variables on both sides interactive notebook page inb foldable math algebra

I did exactly as she said to. I passed out these 6 balanced scale problems to my students. It was shortly after Halloween, so I still had leftover trick or treat candy. I promised candy to the first student who could figure out all six problems. Instant engagement. That instant engagement was, of course, followed by instant frustration.

There are only two rules:

1. Both sides of the scale must balance.
2. Whatever number is placed in one box on the scale must be placed in every box on that scale.

Students have a hard time following rule #2. Of course, the reason they want to break rule #2 is that the some of the problems they are trying to solve are actually impossible.

Finally, I agreed to go over the answers with my students. We discussed 1, 2, and then 4. Oh, my students were SO mad at me. I was loving every moment of this lesson! When I told them that I had lied to them at the beginning and told them all of the scales were balanced, they were not happy. In fact, they decided that I should have to give them all candy since I lied to them. That was my plan all along, of course.