## Witch 106: Plane Silly

We’re snowed, and we have a couple posts in the works that simply won’t behave. So, we’ll just keep the ball rolling with a WitCH, and have you commenters do the work for now. The following is the introduction to planes (a new VCE topic) in VicMaths, Nelson’s Specialist Mathematics Year 12 text.

## WitCH 105: Flippin’ Ridiculous

It’s hard to be believe we haven’t already done this one, since it’s been irritating us for years. But in any case it really irritated us again yesterday during a tute, and so here we are.

The following introduction and example, chosen largely but not entirely at random, is from Cambridge’s Specialist Mathematics 3 & 4. Continue reading “WitCH 105: Flippin’ Ridiculous”

## Witch 97: Independent Unthought

Following on from the group effort PoSWW, this is a group effort WitCH. It is worth keeping the PoSWW in mind, since the zero vector is again a primary source of confusion and error.

The focus is again Year 12 Specialist texts, this time on their coverage of linear dependence and independence. We have already WitCHed this in reference to the previous edition of Cambridge (which remains essentially unchanged on this topic). Readers may feel free to cheat by referring to that WitCH. Although Cambridge’s treatment was and is atrocious, however, the main targets are Nelson and Jacaranda.

## PoSWW 34: Not Working in Parallel

This PoSWW is a group effort, on one of the sub-topics in VCAA’s current curriculum:

parallel and perpendicular vectors

There is minimal guidance in the Study Design on what the sub-topic is intended to cover and, in particular, no definitions of “parallel vector” and “perpendicular vector” are provided. Our specific concern is the role of the zero vector.*

Below are definitions and implied definitions from three current Year 12 VCE Specialist Mathematics textbooks. We have attempted to be as fair as possible, for each text selecting the clearest definitions/descriptions we could locate.

*) One might be inclined to argue that this is a minor concern. For those thus inclined, we’ll address the argument soon with a new WitCH.

## Lividing the Dream

This one is a little old now, and it’s about a Who Cares blog post by Who Cares people. Nonetheless, it has gotten up our nose and we’re going to sneeze the damn thing out. Stand back.

Last month, the Grattan Institute released another of their education reports: Ending the Lesson Lottery. It was no big deal, saying in ninety pages what would have been better said in two, and the EduTsars are not listening anyway. Still a quick read suggested the report was largely sensible, and any plus in this world is a plus.  Continue reading “Lividing the Dream”

## WitCH 82: Graphic Evidence

This one is courtesy of frequent commenter, wst. It’s really a PoSWW, but the ideas may be sufficiently unfamiliar for it to be worth encouraging WitCHlike discussion. It comes from the Cambridge textbook General Mathematics 1&2.

## PoSWW 26: Elevated Concern

Yeah, it’s been a while. We’ve been busy. But, hopefully we’re now back with normal transmission, and we’ll start with an easy one, courtesy of Mysterious Michael. It is an exercise and solution from Cambridge Essentials Year 10/10A.

## WitCH 79: Cos Why Not?

Yeah, we’re busy, but this one has been bugging us. It is an exercise and solution from Cambridge Specialist Mathematics 3&4. It’s basically a PoSWW, or we could simply let it pass as a textbook glitch. But we think there’s more than the obvious to say.

## Yet More Mathematics Books, Free to More Homes

Same as last time, and last last time. This pile is mostly graduate texts, with quite a few classics, but there are also some excellent undergraduate texts, and some oddballs.

Please comment below or email me if you have any interest in any of the books or if you have any questions. Quickly. I’m happy to consider meeting up here or there in Melbourne, but I definitely won’t be mailing any books this time. I’m tired of people not saying thanks.

## Governor DeSantis’s Critical Race Theory and the Rejection of Mathematics Texts

Last week, the big, crazy news out of big, crazy America was the Florida Department of Education’s decision to reject 54 school mathematics texts. The reasons? Well, supposedly the rejected texts

included references to Critical Race Theory (CRT), inclusions of Common Core, and the unsolicited addition of Social Emotional Learning (SEL) in mathematics.

The claim was immediately undermined, however, by the FDOE’s declining to provide any such references, or to even identify the rejected texts. Continue reading “Governor DeSantis’s Critical Race Theory and the Rejection of Mathematics Texts”