Tag Archives: Substitution

Day 172: Substitution Puzzles

For the last few weeks I have been using half the period on Fridays to review. A couple of weeks ago I came across some great puzzles at MathArugments180 (the actual credit seems to go to Mimi). These helped students ease back into solving systems by substitution today. I want to also make a note here for next year to use these as a follow up to Noah’s Ark.


A colleague showed me these puzzles about 4 months ago also… I missed out not using ’em earlier.

Day 97: Noah’s Ark

Algebra wrapped up solving systems by graphing today and moved on to substitution. I found an awesome intro activity over at Fawn’s 180 blog.

The first time through, I didn’t give students enough time to chew on the problem. But, for the rest of the day I gave them 20-25 minutes to work on it in small groups. A lot of students were stumped but no one was unable to at least have a start on the problem. I heard a lot of satisfying sighs of relief today after students solved the problem.

With time students came up with a lot of different solutions, I challenged all them and it was a great activity in developing reasoning.

Here are two example of student work


Several students started by assigning values certain animals and set up a system of equations ISH  approach. It was fun hearing their reasoning of how they reached a solution.
IMG_0543The second example lends itself into a smooth transition for a conversation about substitution.

Great day today!