Thursday 3 December 2015

MPM2D - Day 59: Stuck on Factoring

I planned on looking at perfect square trinomials and moving on to completing the square today, but that did not happen. I had several students tell me that they just weren't getting factoring. I know that this is in part due to some of the "ugly" questions they faced for homework last night, but also that they don't have enough experience to recognize how to factor. I had that internal debate between "we need to move on" and "they don't get it so we need to slow down" and the vibe in the classroom told me I didn't actually have a choice. 

We started by finishing yesterday's work.

Then we factored. A lot. They all may have nightmares tonight of me saying "Is there a common factor?"! Here is a sample:

See how I sneaked in talking about perfect square trinomials? We did another one later and when I said "I know that's a perfect square trinomial", several students asked "How can you tell?" - setting things up for tomorrow! Back to #11 for a minute. Can someone tell me if there is a way of factoring that with tiles without first factoring out -1? I can't figure it out and it's bugging me.

Update: thanks to Hélène Matte for showing me what I couldn't see yesterday (so tired...)

Now I know I lost many of them when we did this one (which I love because I'm weird like that):

but I still think they are ahead of where they were at the beginning of class. The types of quadratics they need to factor to solve problems for this course are not like this. The most complicated are ones where they have to take out a common factor and are left with a complex trinomial. I'm not entirely sure why we ask them to factor all kinds of crazy expressions beyond that we had to do them and some of us really like factoring them.

I feel like I need a separate blog post about what I have done in terms of teaching my class factoring this semester. That is, what hasn't worked well and how I plan on fixing it for next time. However, with a new puppy and the craziness of December (which includes 4 family birthdays in my case), that may have to wait a bit. Feel free to bug me about it though :)

Here is today's homework - I told them they may not be able to do question 1. Thankfully the rest was all lagging homework.

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