In this week’s Aftermaths, Jon and Becky dive into the wonderfully frustrating world of mathematical misuses in everyday life, inspired by a brilliant email from listener Sam Asplund, a Year 4 teacher and maths lead from Ketten Primary School.

After a pupil requested a “cheese square” during snack time — while pointing out that Dairylea “triangles” aren’t truly triangles at all — Jon and Becky go down a joyful rabbit hole of everyday maths errors. From curved-edged cheese sectors to supermarket statistics, they explore the misconceptions we see “in the wild” far more often than we’d like.

This week’s highlights include:

Sam’s pupil correctly notes that Dairylea “triangles” have a curved edge — making them not triangles at all. Cue a debate about polygons, sectors, and whether “Dairylea Cylindrical Sectors” will ever catch on.

Becky’s first maths misuse: believing that something is “due” to happen simply because it hasn’t happened yet. From dice rolls to roulette wheels to lottery numbers, the misunderstanding is everywhere.

Jon unpacks how mean and median can tell very different stories — and why politicians love using whichever version suits them best. If you've ever wondered why the “average salary” feels inflated… this segment will speak to you.

Becky explores how easily people mistake coincidence for cause — from homework to exam results, leafy diets to lifestyle habits, and even the old myth about storks bringing babies.

Jon rounds things off with the problem of tiny samples, big headlines, and percentages designed to impress rather than inform. (“Burglaries up 200%!” doesn’t mean what you think.)

Becky shares her takeaways from Jon’s interview with Rob Eastaway, including:

• Why written methods rarely feature in “real-world maths”
• How puzzles inspire genuine mathematical thinking
• The importance of estimation
• Making space for curiosity, conjecture and open-ended exploration

Got a favourite maths error you’ve spotted in the wild? Email: [email protected] — Jon and Becky would love to feature it.