Tuesday 1 December 2015

MPM2D - Day 57: Factoring & Speed Dating

It is interesting to watch a class of teenagers arrange the desks given only verbal instructions. They eventually got them into two rows, facing each other. I told the class that they would be speed dating this morning, which caused a few raised eyebrows. Then I said factoring speed dating. I gave each student a piece of paper (half of an 8.5" by 11" sheet) upon which was written a quadratic expression. Their first job was to factor that, below the fold line. They also had to check their work by expanding and simplifying their answer. They were now each the expert on factoring their quadratic.

Once everyone was ready (and I took care of the one quadratic that didn't factor - oops) they got ready. They each factored the quadratic opposite them. I started the timer at 1 minute which turned out to be too short - we settled on 1:30 for each round, then cut back to 1 minute once they were all sure of what they were doing. I also got some background music going as it seemed too quiet. They each ended up factoring 13 quadratics in a much more fun way than just giving them a worksheet and saying factor.

We spent the remainder of the period working through examples together.

Beyond just getting more practice, we focused on noticing. Noticing when there is a common factor and how dealing with that simplifies the resulting trinomial. Noticing that if the product is negative the numbers must be positive and negative, and if the sum is negative, then the absolute value of the negative number must be bigger than the positive number (that's really not how we said it though!). Noticing what is special about a difference of squares. I still don't have a good feel whether they "get it", but once I look at yesterday's homework, I should have a better sense of what we need to do tomorrow.

Here is the homework for the next few days. I asked them to do the first box tonight.