On Tuesday night I gave an hour's tuition to a 16-year-old Takapuna Grammar boy. He'll be doing the same exam as the girl from Remuera, only he's not quite at her level. His arithmetic was fine but his algebra needed a lot of work. I asked him to solve the equation (

*x*-4)/2 = 7 for

*x*. "Can't I just say it's 18? he said. Well, yes I suppose, although I'm not sure whether you get all the marks in the exam if you just slap down the answer. I then gave him the very similar expression (

*x*-4)/2 =

*a*and asked him to make

*x*the subject, but he was all at sea there. I can understand how he finds the transition difficult. I always found numbers easier to handle than

*x*'s and

*y*'s. But I think a major reason why a lot of people find algebra difficult is that they just learn a bunch of rules to get them through their next test or exam, without knowing

*why*they're applying those rules. For instance this kid could solve a quadratic equation like

*x*² + 7

*x*+ 10 = 0 with no trouble, by finding two numbers that add to give 7 and multiply to give 10, but didn't know why that method worked. Of course he might also like to know why you'd want to solve a quadratic in the first place, and I can't help him there. I hope I can help him get through his exam in mid-November though.

After an icy blast early in the week things have warmed up again. On Saturday I've got the Asperger's group to look forward to.

"Firstly, from now on I'll be moving all those deadly dull poker posts to a separate blog which I've called Plutoman's Poker Planet, so you'll spared all that badugi bollocks in future. Phew!"

ReplyDeleteAs soon as I read that sentence, I subscribed to "PPP".

Ha! You'd be a good poker player I imagine. Your chess background would come in handy I'm sure. "What does he think I think he's got?"

ReplyDeleteAny tips on teaching basic algebra BK?