MPM1D1 - Day 40 Surface Area

We had a guest in our class today. I had a meeting with a teacher from another school this morning and he decided to stick around and check out my class. It's always nice to have visitors. Teaching is often done in isolation. It's nice when we can get together in a classroom and reflect afterwards. We need to do more of this. At some point I need to make time to get #observeMe going.

We started the day with this visual pattern:

I asked students to find an equation that represented the surface area for step n. I handed out the linking cubes and students went to the boards. Some began building the model, others quickly made a table (of values, not an actual table made of cubes). Many just made a table for the number of cubes. Others tried using a formula, without giving it much thought. Still others tried to reason their way through only to fall back on 'the formula'. When  groups got stuck with their chosen formula I asked what surface area was (we haven't really talked much about it in class). Everyone I asked was able to tell me it was the area of all the faces. I asked them to forget about the formula and find the surface area using the cubes they had in their hands and off they went. One group wanted to find the surface area of the rectangular prism then subtract the exposed surface of the cube that was missing. I asked what happens when they take out the middle cube and they realized that they would have to add in the surface area of centre. An neat approach.

Some groups finished the task quickly while others took a long time to get there, but did manage eventually. Once they were done I had them work on these problems at the board. There were lots of great discussions (especially about the Pythagorean Theorem). Today seemed to be one of those days that things just flowed smoothly. I guess having two adults in the room can do that.

With fifteen minutes to go we did a mastery test on finding the equation of a line and I handed out some practice questions for students to work on individually.