Think-a-Gon: Mathematical Reasoning Puzzles

Think-a-Gon games reward strategy over speed. Number Detective and similar puzzles ask students to test hypotheses (“if I assume the missing number is 7, does the pattern still work?”) — the same pattern of thought used in AMC 8, Math Kangaroo, and SASMO problems. The difficulty curve is steep enough to give able students something genuinely challenging without breaking confidence.

Pair this collection with the Math Olympiad printables in our Printables hub. A typical week for a competition-track student: two short Think-a-Gon sessions to warm up reasoning, followed by one printed past paper. The interactive games keep motivation high; the paper paper builds endurance for full-length contests.

The collection currently contains 5 live games. Featured picks include 4x4 Magic Square Solver (Arrange 1-16 so all rows, columns, and diagonals sum to 34 with solver assistance); Undercover Sum (Some cells revealed — use row and column sums to deduce the hidden numbers); Grid Sum (Empty grid — fill numbers so every row and column matches the sum clue); Pyramid Sum (Each pyramid cell equals the sum of the two below — fill in the missing ones). Each game has been chosen against the topic’s key skills rather than for sheer volume — every entry maps cleanly to a small, assessable goal a teacher could mark in two minutes.

Games in this collection cluster around G5, G4, G6 and span 2 difficulty levels, which means a single student can stay in this category for multiple semesters without needing to jump to a different topic to find appropriately challenging work. Pair this collection with our Printables hub for the highest-yield routine: 5–10 minutes of digital game warm-up, one timed paper practice sheet, then a short verbal review of any misses. The screen–paper–verbal rotation is the practice pattern with the strongest evidence base for transferable fluency gains.