Free maths challenge cheat sheet: tricks and traps (PDF)

The challenge papers are puzzles, and the same few tricks come up every year. In each multiple-choice question, one of the five options is the answer you get from the obvious mistake. The first page shows those traps, each with a worked example: counting the gaps instead of the posts, forgetting that everyone gets older together, rounding up for packs, fast and slow clocks, pairs counted twice, full and part full, counting digits, and misreading the question.

The second page has the question types that keep coming back and the method for each: two shopping lists, Venn diagrams, order puzzles, shape equations, working backwards, counting triangles, divisibility checks, fractions of an amount and rectangles twice as long as wide. It ends with how to sit the paper. Every example on the sheet is our own, and each shows the tempting wrong answer crossed out beside the right one.