## Thursday, 5 March 2015

### MFM2P - Day 22 (Finding Angles with Trig)

They mostly worked in groups on the big whiteboards. Many groups wrote 50 x 3 = 150 and 25 x 5 = 125 and they circled the second calculation as the better option. But what did the 150 and 125 mean? They couldn't tell me. One student even told me that those numbers had no meaning. This was the big takeaway for my class - just because you have numbers doesn't mean that you should necessarily start calculating with them. We discussed how the 50 lb box would be harder to carry up that third flight of stairs than it was for the first flight of stairs. Some told me that 50 lb wasn't heavy so they were okay with carrying that instead of the 25 lb box. There were interesting discussions and they agreed that this was an opinion question (because they don't have the physics background to work with) and it depended greatly on their level of fitness and how strong they were.

Today I was bound and determined to finish Boat on the River 3-act. But we didn't. Sigh. I started by getting them to add a "find an angle" trig question to their exercise books:

and I thought this would be an excellent opportunity to review sum of squares so we did that for the same triangle:

They practices a few more trig questions (finding the angle, only) before the quiz. Open-book, again. Some similar triangle questions followed by sum of squares and trig. I was pleased that when some of my students seemed stuck, they responded really well to a quick prompt from me. I also really loved it when a student asked for highlighters for the similar triangles questions.

No time for Boat on the River, but I will get back there!