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<\/p>\nWhile my Year 9 class is starting to move on to Area and Volume, I’m still quizzing them on Expanding and Factorising. At the start of Monday’s lesson, I planned to hand out a short set of factorising practice questions to warm up with.<\/p>\n
At least, that was the intention. As it turned out, I only remembered that when I walked in the classroom door.<\/p>\n
I could’ve moved straight onto the main activity for that lesson, but I still wanted to do some factorising questions first. So I did what any teacher does when they forget something – pretend that’s what the plan was all along. As it turned out, the accidental result was better than my original plan.<\/p>\n
I asked students (some volunteers, some I picked on) to give me examples of expressions that can be factorised, which I wrote on the board. I gave everyone a few moments to factorise them, then the class gave me their answers:<\/p>\n
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(I’m so sorry for my scrawling handwriting. I’ve never really had the patience to write on the IWB neatly.)<\/p>\n
The third one was really interesting. Obviously it can’t be factorised, and my reaction at the moment it was suggested was to say that, but fortunately I held my tongue and left it there. That question mark represents a really good discussion the class had about whether this counted as factorising or not. Also, it was awesome that most of the class had already recognised that 1 was the highest common factor of the two terms. They decided it wasn’t factorising, because multiplying by 1 doesn’t change the expression, and it didn’t help simplify the expression.<\/p>\n
This is one benefit of getting the class to suggest questions. Had I remembered to organise questions before hand, I would not have used a question like this and not led to that discussion.<\/p>\n
I pointed out that all the questions had a numerical common factor. “Is this the only type of factorisation?” I asked. This led to a whole new round of student given questions:<\/p>\n
![\"\"](\"\/content\/images\/2014\/Aug\/factorising2.PNG\")
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With these, I love how a couple of students recognised that using x2<\/sup> allowed them to make x the common factor. I also love how the last student refused to allow that pattern to continue, so looked for a different example. There’s much deeper thinking going on here – rather than just giving the answers, students were able to think about and discuss the nature of expressions and how they can be factorised. Which is pretty cool for a warm-up activity I didn’t plan.<\/p>\n","protected":false},"excerpt":{"rendered":" While my Year 9 class is starting to move on to Area and Volume, I’m still quizzing them on Expanding and Factorising. At the start of Monday’s lesson, I planned to hand out a short set of factorising practice questions to warm up with. At least, that was the intention. As it turned out, I … <\/p>\n