Lindsey Kuper (lindseykuper) wrote,
Lindsey Kuper

Why do they teach you long division?

Jamie jwz Zawinski quotes Steve Yegge on long division: "Why do they even teach it to you?"

When I learned division in fourth grade, they started us out with plastic cups and piles of beans before they taught us how to do anything on paper. Then, when we switched over to doing it on paper, they told us how each aspect of the moving-beans-around-on-our-desks thing mapped over to the moving-numbers-around-on-paper thing. Some of us were able to make that cognitive leap, and others of us weren't. But I doubt that any of us would have been able to make the cognitive leap from moving beans around to understanding why a calculator works. Most adults can't do that. Hell, I bet most adult programmers can't.

If nothing else, I think the long-division procedure gets you playing around with numbers, and maybe noticing patterns that you wouldn't notice if you just gave your calculator the divisor and dividend and got the quotient. Some of those fourth-graders are going to wonder just why the long-division procedure works, anyway, and I bet some of them are going to be able to figure it out. And even if they never wonder about why it works, I think there's still a certain MacGyver-ish thrill to being able to do it, a "hey, look what I can do with just paper, pencil, and my brain" thing.

If they were using a calculator to begin with, then I bet that some of them would also wonder why that works -- as well they should! But that's a pretty freakin' huge can o' worms they're opening, and they're in fourth grade, and they'd be more likely to get discouraged if they tried to figure it out.

But heck, I dunno; maybe we should be starting kids out by teaching them the logical operations, or teaching them about sets, instead of teaching them arithmetic. Math is big and there are a lot of places to start.

Tags: nablopomo 2006, programming, signal, teaching

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