Our first unit is Expressions and Equations. The first few lesson are mostly a review of what was taught last year – combining like terms, the Distributive Property, etc. Because this was a review, I wanted a different, memorable way of discussing combining like terms.

Sarah at Everybody is a Genius wrote a blog post about having her kids sort school supplies at the beginning of class. I borrowed this idea and put three plastic cups on each table. Inside each cup was a mixture of dice, octagon shapes and dominoes. As the kids entered the room, I instructed them to sort the materials for me. I complained the other class made a mess.

Unsorted Materials: (can you guess what a possible issue with this will be?)*

My kids are awesome and immediately got to work. Almost* all the kids put the yellow octagons into one cup, the dominoes into another, and the dice into a third cup. I asked the students why they separated the dice from the dominoes, etc. and I could almost see the light bulbs above the kids heads as they began to shoot “combining like terms”!

Sorted Materials:

*My mistake, or opportunity for a great discussion, was the colors. Some kids sorted the items by colors – all the red dice and red dominoes went into one cup. The yellow octagons and yellow dominoes went into another cup. The kids that did this told me they figured this was another WODB and there would be more than one right answer. Good thinking on the part of the kids! Next time I will make sure to use **one** color for each item!

Next, I wanted to use the “orange-mallow” demonstration I read about somewhere within the MtBoS (if you know who had this idea originally – let me know and I will give credit and link!) The idea is you have oranges and marshmallows. You put three oranges in a bag and ask the kids how many oranges are in the bag. You take an orange out and repeat the question, etc. You then add a marshmallow into the bag and ask again how many **oranges** are in the bag. The kids instinctively keep the oranges and marshmallows separate – there’s no such thing as an orangemallow. Then, throughout the year, when kids make a mistake with combining like terms, you can say “no orangemallows”. We have a **very strict** no food policy at my school. Even though the kids would not be eating (or touching) the food, there is still a great deal of paperwork and red tape involved so oranges and marshmallows were out. Instead, I used what I could find in my classroom – dice and these adorable mushroom erasers.

I added three dice to a bag and asked, “How many dice are in the bag?” I took once out and asked the same question. I put four dice in the bag and asked the question again. I then added a mushroom and asked the same question. One student said “six dice”. Another added “and one mushroom”. Perfect! I then asked, “Why didn’t you say we have seven mush-dice, or mushy dice?” The kids were able to tell me the items were different – and made the connection to combining like terms. However, they didn’t seem all that impressed with my demonstration. Some almost seemed insulted. I was somewhat disappointed. Maybe it’s because the idea of combining like terms was not new? Maybe mushy dice isn’t as cute or funny as I thought? Was this a waste of class time?

Flash forward a week or so – we’re practicing solving equations with variables on both sides. Kids are asking me to check their work and inquiring why an answer isn’t correct. I point out where they have combined terms that are not alike and say, “You have mushy dice”. I get smiles. I start to hear the students say “no mushy dice” as they check in with each other. Maybe the demonstration wasn’t a total bust. 🙂