Somewhat biased questioning methods here?! And someone at this company (which as far as I can gather is a broker of brokers of insurance companies) will be proudly reporting how many people complimented them (100% of those surveyed!)

It's that time of year again - anyone with students who can do volumes of revolution might like to calculate the volume of a creme egg from my implicit equation:

If we create a distribution from a subset of the normal distribution, we usually lose symmetry. In this one, we can calculate the mean using improper integrals (the centre-of-mass formula turns the Gaussian integral into a simple inspection one), and we get a mean of sqrt(2/pi).

Tip for anyone who uses Eratosthenes sieve with students to filter for primes: with lines of 21, all the early primes make nice lines (3 and 7, the sneakiest ones, are both vertical lines, and the rest are 45 degree diagonals).

My students wanted to know if they could bring my 'sine ruler' into their A level Maths exam. Not hugely surprised that the answer was 'no', but the reason surprised me! Apparently students aren't even allowed a normal ruler! Is this common knowledge??

I made a thing!

Used @geogebra.org to create 3D versions of polar curves so I could print them. SOO helpful for teaching integration when you can physically see the overlapping regions and trace the shape with your finger. Increasing theta is in the z direction.

I love breaking the unspoken rule about fraction diagrams (all pieces congruent, not just equal in area). Here are a few of my favourite non-standard representations. A one radian sector fills half the unit square, the curves y = x² and y = √x enclose 1/3 of the square. Can you come up with more?

Quite pleased with this little @geogebra.org animation of mine - shows how the area of a fixed perimeter rectangle changes as we vary the side length.

Rock-Paper-Scissors-Minus-One: what if both players had to reveal what they were about to play in advance? More mathematically interesting than it might sound... youtu.be/Xv7PnN5vVaU

Using p5js to create an animated version of the 'paceometer' seen in a @rorysutherland.bsky.social talk: youtu.be/Bc9jFbxrkMk. editor.p5js.org/thechalkface...

Using TinkerCad to design a replacement part for my retractable Stanley knife. At this rate, I only need to break another 40 or 50 household objects and the printer will have paid for itself ;)

@sparksmaths.bsky.social Been trying to model your Binomial-not-binomial data with some Terrible Python Code (tm). Any chance I can access your weird data? Simulating different drop-out rates and want to chi-squared against your actual data. I attach a @geogebra.org visual to get your attention ;)