TNDOT 3: The Remainders of the Day

Here’s a third entry in our Teaching New Dogs Old Trigs Tricks series: the first three questions from the 1907 Victorian Matric Algebra exam.* As well as the computational aspects, readers might be interested in contemplating what was expected for the proof parts, as well as how one might fruitfully present such results to students now, a century later.

*) TNDOT 2 is also in the process of being updated. Stay tuned.

Continue reading “TNDOT 3: The Remainders of the Day”

PoSWW 37: Squaring the Circles

This one comes courtesy of Mystery Fred. The diagram above is for a Circle Gaps Brainteaser, and appeared online last week as part of Double Helix, CSIRO‘s science magazine for kids. The text for the brainteaser (as if it matters) is as follows:

What is the area of the orange star in the centre? The blue circles each have an area of 3 square centimetres, and the big square has sides that are 4 centimetres long.

A comment on the post makes it clear that the choices of sidelength and area were purposefully made.

Continue reading “PoSWW 37: Squaring the Circles”

NotCH 6: Not Abbott’s and Not Costello’s Mulsification

 

We have the bigger projects (AC, ITE, SD) in the works, plus an FOI appeal to do, plus 2000 words for a lefty magazine due in a couple weeks. We’re kinda busy. But, we’ll try to keep the general posts ticking along. This one is some fun, plus some history and a couple of puzzles.

One of the all-time great maths scenes is Abbott and Costello’s famous bit, where Lou Costello proves that 7 x 13 = 28:

Continue reading “NotCH 6: Not Abbott’s and Not Costello’s Mulsification”

Puzzling Souls

We’re a little out of steam right now. Some big posts are planned, but it’s difficult to gather our strength to write them. In the meantime, we’ll keep things going with a few light and easy posts.

A while back we posted some (still unanswered) puzzles by Tony Gardiner, as well as the excellent article by Tony from which they came. Exploring Gardiner’s writing a little further, we stumbled upon a hilarious problem, from long ago. Continue reading “Puzzling Souls”

NotCH 2: A Digits Puzzle

OK, hands up who thought there was ever gonna be a second NotCH?

We’re not really a puzzle sort of guy, and base ten puzzles in particular tend to bore us. So, this is unlikely to be a regular thing. Still, the following question came up in some non-puzzle reading (upon which we plan to post very soon), and it struck us as interesting, for a couple reasons. And, a request to you smart loudmouths who comment frequently:

Please don’t give the game away until non-regular commenters have had time to think and/or comment. 

Start by writing out a few terms of the standard doubling sequence:

1, 2, 4, 8, 16, 32, 64, etc.  Continue reading “NotCH 2: A Digits Puzzle”

NotCH 1: Maths Masters Quizzes

More or less by accident, this post is the beginning of a new series: Not Crap Here.

A couple of people have suggested that we could occasionally include Dr. Jekyll material on this blog. You know, helpful stuff. It’s a decent idea, if our current thoughts weren’t so influenced by misanthropic disgust and murderous rage. Still, we’ve received two specific requests for the same old Jekyll material,* and which entailed some digging. Having finally dug, we’ve decided to post the material here, for whomever is interested. Whether or not there will ever be a NotCH 2 is anybody’s guess.

Continue reading “NotCH 1: Maths Masters Quizzes”