Tom Lehrer - New Math (Animated)

My favorite Tom Lehrer song is probably New Math. ▶ this video With its clever lyrics and rapid fire delivery it sounds like it could have come out last year and not fifty years ago.

in “Tom Lehrer at 90: a life of scientific satire” · View on HN

Yes, he's mocking the idea of teaching borrowing. He gives the way he thinks subtraction should be taught in the intro. It's a way that, as far as I can tell, hasn't been taught in America in over half a century. After the intro, he goes on to mock the concept of borrowing, which was (apparently) part of New Math. Then in the final verse he mocks the idea of teaching bases. Here's a good animated version of the song that shows the different methods. You'll notice that the "silly" New Math method is the way that makes sense to Americans today, and the "simple" method preferred by Lehrer is very confusing for anyone who's not used to it: ▶ this video Here's more of the intro which makes it clear what's going on. My explanations in brackets: > Some of you who have small children may have perhaps been put in the embarrassing position of being unable to do your child’s arithmetic homework because of the current revolution in mathematics teaching known as the “New Math”. > So as a public service here tonight, I thought I would offer a brief lesson in the New Math. Tonight, we’re gonna cover subtraction. [ New Math is confusing, and he's going to go over how confusing it is in a humorous way.] > Consider the following subtraction problem, which I will put up here: 342 minus 173. Now, remember how we used to do that… > Three from two is nine, carry the one, and if you’re under 35 or went to a private school you say seven from three is six but if you’re over 35 and went to a public school

in “Why did Tom Lehrer swap fame for obscurity?” · View on HN

Yeah, ultimately it's the same algorithm, it's just a question of what are the details of the procedure, which makes it confusing if you've learned one way and not the other. The whole point of the song is that Lehrer thinks this is a new, less good way of doing subtraction. Look at this video if you haven't already: ▶ this video The first way he does it seems INCREDIBLY confusing to people who learned arithmetic in the last 30 or so years (the sentence "8 from 4 is 6" is nonsensical to most such people), but the "modern" way he's mocking is perfectly understandable. I think the song is very funny and charming, but I do think this is a rare case where Lehrer is just wrong, the "borrowing" style is a much better and clearer way to explain subtraction. It is just as fast, and it gives you a much better intuition about what's actually happening, instead of just learning the steps by rote.

in “Why did Tom Lehrer swap fame for obscurity?” · View on HN

It's inevitable to link to this now: ▶ this video It's Tom Lehrer, about 50 years ago, explaining subtraction in the context of the "new" math (the base-8 stuff starts at 2:40). Worth a listen.

in “A ridiculous Common Core test for first graders” · View on HN

Pounding the dust out of the erasers was something American students often found fun, especially as elementary school students; this is referenced in the Tom Lehrer song "New Math": ▶ this video

in “Why do Stanford math professors still use chalk? (2021)” · View on HN

A whole lot of "I think", "I believe," "I feel". No reference to existing educational research on what works and what doesn't. >This isn’t a call to give up, though: instead, we should teach maths differently, in a way that doesn’t churn out mathophobes. When five-year-olds first encounter the subject, it’s as a creative, open-ended activity, involving play and exploration. They learn about numbers using colourful blocks that join up in different ways. They fit these shapes together and tell different stories with them. Just a year or two later, though, maths becomes a discipline with strict rules and a forbidding regime of right or wrong answers. Instead we should try to maintain that sense of exploration and open-endedness, of trying out different approaches to a problem and seeing what works. What’s important about times tables, for example, is not the answers, but the different possible relationships between numbers. What’s important about equations is not the solution, but the techniques we use to untangle a problem using logic. Some of these exercises could be presented more like a Sherlock Holmes mystery, where the focus is on how the clues are pieced together and not just on what the answer must be. Where's the evidence that this would actually be a superior teaching method? The point of drills is to counteract the natural tendency to forget things. Fluency is gained through practice and repetition. There's no way around it. Think of an actual Sherlock Holmes mystery

in “What if nobody is bad at maths?” · View on HN