While talking with an 8th grade teacher today, I was reminded of a lesson I've done in the past about combining like terms. I wanted to write a quick post to share and also so that I can have it saved to refer back to.

The lesson begins by showing this clip:

The kids always laugh and enjoy the silliness of it. When it keeps going, I hear a lot of "You gotta be kidding me!" and "ugh, how long is this going to go on?" Perfect. I feel like I'm creating the controversy (create the controversy, Dan Meyer suggests is a first step)

After the video, I talk about a simpler version of this same idea.

**Me:**What if I ordered 5 hamburgers, 3 orders of fries, 6 hamburgers, and 2 more orders of fries. Is there a better way to order that is less confusing?

**Students:**Yes! (they are almost frustrated with me!) Put the hamburgers together and the fries together.

**Me:**Oh, so if I wrote ((write on the board: 5h + 3 f + 6h + 2f)), how would it look if I combine them? ((notice I start using the word COMBINE))

**Students:**Yes! 11h and 5f!

**Me:**((I record on the board. 11h + 5f)) Like this?

**Students:**((now wondering how I have a job as a math teacher if I'm having this much trouble. I love playing to this and creating the headache for students! Make them do the thinking!)) Yes!!!

**Me:**So the

*coefficient*of 11 means I have 11 h's and the coefficient 3 means I have 5 fries? ((start using the vocab that you want students to know. Using context clues, students start to realize what I mean by the word))

I go on to show other situations and move towards using x and y. Also pose questions that include subtraction. Also, asking, "what if there was a negative

*coefficient*?"

I would love to hear how you imagine using this clip to introduce combining like terms!

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**Postscript: The idea using this video with a combining like terms lesson was not original to me. I found it online a few years ago. I can't find the original source of the idea. Was it a blog? A website? I can't remember. I also don't remember

*how*the original poster suggested using it. However, send me a note or tweet if you know where this idea was first suggested. It certainly is a creative idea and worth "stealing," as all good teachers do! :)

Great idea! Love the"hook" at the beginning to get students engaged!

ReplyDeleteI would love to use this, but the clip will not work! Do you have the direct link?

ReplyDeleteTry this: https://www.youtube.com/watch?v=M2T7Z8PwESY

DeleteLet me know how it goes if you use it in your classroom! :)

I LOVE THIS LESSON! Pulling kids into the lesson (with something so annoying) and making a real connection with math!!!

ReplyDeleteNice job! While some kids will thrive if we just give them a messy example, my experience say that your hook is much more impressionable. I suspect you later referred to the fast-food order many times later (a 2-second reminder). "Messy example" would not likely be so quick.

ReplyDeleteThank you so much for this! I am going to use it in an 8th grade unit where some students struggle to see why simplifying expressions is important. I am also going to make one small change: Instead of asking how to represent an order of 5 hamburgers, 3 orders of fries, 6 hamburgers, and 2 more orders of fries, I will ask how to represent the COST of 5 hamburgers, 3 orders of fries, 6 hamburgers, and 2 more orders of fries with h and f representing the cost of those items. I worry that without that clarification it might fuel the misconception some students have that a variable is an abbreviation for a word instead of representing a value for a number (which causes students to think that 4Q=1G). Again thank you so much for this I know the students are going to love it.

ReplyDelete