Posted in puzzles.

When Jake’s father (Bradley Whitford) comes to town, Jake is excited to see him, but Charles is wary of his intentions; Holt challenges Amy, Terry, Gina and Rosa with a brain teaser in exchange for Beyonce tickets. Brooklyn 99, S02 E18, Captain Peralta “Surely it isn’t that hard?” I have

Read More →
Posted in ask uncle colin.

Dear Uncle Colin, I’m trying to work out $0.03 \div 0.1$. The answer is apparently 0.3, but I don’t understand why a division would make something bigger! Division Isn’t Very Intuitive, Decimals Especially Hi, DIVIDE, and thanks for your message! There are several ways to tackle this. I’ll start with

Read More →
Posted in dome.

I am not a number theorist. I mean… well scratch that. I am not an especially knowledgeable number theorist1 but I do enjoy number theory when it’s around my level. The Sieve of Sundaram is about my level. What is the Sieve of Sundaram? OK, let’s start with the Sieve

Read More →
Posted in ask uncle colin.

Dear Uncle Colin, I need to find the area between the graphs of $y=\sin(2x)$ and $y=\cos^2(x)$ in the interval $0 \le x \lt 2\pi$. I’ve found four solutions, but I think that means I need to do five separate integrals! Is there an easier way? Trigonometric Expressions: Double Integration Of

Read More →
Posted in factorising.

The marvellous @solvemymaths tweeted some time ago about finding least common multiples and highest common factors: I know the Venn diagram method for finding the Lowest Common Multiple is supposed to make it easier, but in my brain it just makes you do more maths. Also circumvents understanding if you're

Read More →
Posted in podcasts.

In this, the final episode of WBU, @reflectivemaths and I discuss: @samuel_hansen's antiracism post((get well soon, Samuel)). Dave and I both assert that Black Lives Matter and acknowledge that we have a significant amount of work to do to create a just society. In a whiplash-inducing change of tone, tooth

Read More →
Posted in ask uncle colin.

Dear Uncle Colin, I have been presented with this diagram: the marked points are a third of the way along the sides. I need to know what fraction of the grey square is shaded blue. Any ideas? Somehow Hued Area Defies Evaluation Hi, SHADE, and thanks for your message! There

Read More →
Posted in puzzles.

Once upon a time, I was a sudoku fiend. They provided an outlet, a distraction, a hiding place – I could bury my head in one for, say, half an hour and whatever had been troubling me before was somehow less of an issue. It’s not an effective strategy for

Read More →
Posted in ask uncle colin.

Dear Uncle Colin, I have an octahedron, and I’m not afraid to use it! But I am afraid to find the angle between two adjacent faces. How would you do that? Protractors Lack Accuracy Tackling Octahedron Hi, PLATO, and thanks for your message! An octahedron is a shape made from

Read More →
Posted in sport.

Last week, the English Football League season was cancelled, with standings decided on a points-per-game basis in League One and League Two1 In League One, that led to Wycombe Wanderers leaping into the playoffs at the expense of Peterborough, who had accrued the same number of points but played a

Read More →