## Friday 17 April 2015

### MFM2P - Day 46: Multiplying More Binomials & Finding Zeros

I wasn't sure if it was perfect timing or terrible timing when I realized that today's warm-up was this:

Given what we did yesterday, I expected to see a lot of boxes used to calculate this product. I did see more than I likely would have normally, but we got lots of different methods which we shared:

I showed them that you could double one of the numbers and divide the other by 2. I really like being able to see how my students think and having them explain their method to the class.

We then continued with the work from yesterday. We started by restating the zeros for each of the graphs and then tried to make sense of them.

I put up a different equation, y = (x + 7)(x - 9) and the student I asked told me that the zeros were at 7 and -9. So I pulled up the graph on Desmos and asked what he thought.

He opted to change his answer to -7 and 9. Then we talked about why they are called zeros - it was great to have the Desmos graph with the points showing the y-values as I did this. We discussed why the signs for the zeros are opposite to the corresponding numbers in the equation.

I'm not convinced they were all following (I should incorporate some formative assessment at this point next time), but they did at least all see that the signs were opposite.

They practiced multiplying binomials a couple more times as they added to their exercise books:

Then we moved on to a great matching activity, found here. This was created by the good folks at Sir Wilfred Laurier Secondary School. My students all did some cutting and some gluing but didn't finish anything so I got them to paper clip their pieces together and place their work in a large envelope so that we can continue on Monday.

As a side note, I know that some teachers don't like ending the class without finishing the activity. I have come to like it as it gives us a great starting point for the next class. There will be no need for instructions on Monday - just get back to it. It helps them remember what we were doing, ensuring continuity in their learning.