A mundane looking question that my year 7s are doing now. A pupil decided to convert the numbers to decimals first. Rather than stop them and do the obvious fraction arithmetic, I let them carry on...

We discussed how x and y were recurring decimals, which made the multiplication seem absurd. But they did get to 4.999..., at which point we discussed how this is equal to 5, by considering the difference between 4.999... and 5

and so a seemingly dull question became interesting!

Inspired by some of the wrong answers given by a class today, no real names used of course:

Factorising is a lot more conceptually challenging than we give it credit for. Factors of a term like 6n^2 are very fiddly to explain because n is not necessarily an integer. Any suggestions on how to do this?

inspired by some scary answers to a multiplication question I asked:

An open middle style problem I've just created in a desperate attempt to make something interesting on place value:

One of my students was struggling to understand rotation about a point today, so I made this in desmos: desmos.com/calculator/yre… I'd like to upgrade it to rotating about an arbitrary point but it's restricted to rotations about the origin for now

This feels like one for Andrew Blair, PhD

some Pythagoras questions I've made

A task for a lesson on 1-step equations that I'm trialing tomorrow. Could be extended to a bigger pyramid.

Just found a nice simulator for two-dice totals: geogebra.org/m/UsoH4eNl Should go well with this classic probability task that's long been my go-to when teaching sample space diagrams:

The image is from the GCSE maths specification. Please could someone explain the difference between estimation and approximation?

a sneaky congruence question I made today:

In a lesson today, the misconception in the image came up. I usually just say "it's simply not true" and use the numerical example that root(3^2+4^2) does not equal root(3^2)+root(4^2). But this still seems a bit of a weak response to me. Any suggestions?