Jonathan Payne

This is a terrifying sentence

And overall difficulty is of course definitely above what would ever be expected at GCSE

I think calling it 'just-about GCSE level' was a bit too much of a stretch! Thought was that something like 'prove that the square of an odd number is one more than a multiple of 4' doesn't require any mod arithmetic heavy-lifting.

The most surprising thing doing this was what the product of the gradients of the tangents is in terms of a, b and c

Was playing with generalising a question from the new Edexcel EMC when I cam across this interesting fact. Nice to be able to come up with a question which combines algebraic proof and coordinate geometry. All just-about GCSE level

It's from the textbook for Edexcel's new L2 Extended Maths Certificate

Pretty significant misconception to be stating as fact in an official textbook from an exam board

Thanks

I’d be curious about reading this. Do you have a reference? Thanks

Text reads: A baby was born in July. What month will it be on their birthday 15 months later?

'Interesting' understanding of how birthdays work from ChatGPT here...

An isosceles trapezium ABCE with parallel sides AB=12cm and DC=6cm, and angle DAB=60°. A square ADEF is joined on the the side. Angle FBA is marked as x

ABCD is an isosceles trapezium and ADEF is a square.

Find the size of angle ABF.

A quadrilateral ABCA, with vertices A(0,4), B (0,2), C (2,0) and D (5,0)

Does quadrilateral ABCD have a pair of perpendicular opposite sides?

Very nice - love a proof by folding

And an animation of it in geogebra, because why not

A neat fact about quadrilaterals I found out about today: If the diagonals are perpendicular and equal length, then the midpoints of the sides form a square

Four fractions: 16/64, 19/95, 26/65, 49/98

What's funny about these four fractions? I guarantee you'll hate it

A combinations/listing question disguised as a ratio question:

Given four numbers a,b,c,d such that:
- Two of the numbers are in the ratio 1:2
- Two are in the ratio 1:3
- Two are in the ratio 1:4

How many possibilities are there for the ratio a:b:c:d ?

Strong agree. I think being clear on the distinction between rational numbers and fractions clears up some much stuff conceptually

All the Koch snowflakes bounding the edges was also unexpected

Been playing with tree fractals. The ratio needed between line lengths to make this line up properly was a pleasant surprise

Oh, there's also a really nice and simple general rule for when this works (but I *think* this is the only integer solution)

This is an interesting pair of percentage calculations

Some MATs have pay scales for ordinary teachers which are above the national pay scales

A fun combinatorial question: Given a<b<c<...<h<i, how many ways are there of arranging a-i in a 3x3 grid such that every row and every column is in ascending order?

Now need to get myself a proper profile pick and do a proper bio

It looks like bluesky’s moved past the phase where every other post was about people leaving twitter. So I’m a bit late to the party in doing a ‘deleted twitter and moved properly to here’ post…