Both Algebra and Geometry started off with mental math. There were some great solutions out there, here are a few from Geometry.
- Red: I multiplied 9 by 5 and 70 by 20, so they are equal.
- Blue: I am more comfortable with 80 than 79 and 30 than 29.
- Green: 25 times 10 is 250, then multiply that by 8 to get 80 times 25. Then subtract off 25. Same idea for 75 times 29.
- Black: I wanted to multiply them both by the same number so I took 5 away from 25 and added it to 29. And I took 9 away from 29 and added it to 75.
I then shared a blog post with Algebra and talked about how I was in the same boat in college. My favorite quote at the moment:
“But the truth is anyone can get math. Some of us just have to work harder. Some of us didn’t get the message that you have to practice. We didn’t get that math is really explaining how to solve a problem, not just solving the problem in front of you.”
After both classes worked on different Row Games. Geometry didn’t quite finish but in Algebra we talked about this question after:
I told them I was much more interested in how they started the problem than the solution. All the different ways student’s started the problem were interesting and we had some good discussions over adding a negative and subtracting a positive.