Puzzle thinking, competition style

Challenges run daily, weekly and monthly — from number sprints to olympiad-style rounds with live leaderboards.

Method, step by step

1. 1

   Target 24. Notice 6 × 4 = 24, so try to build a 4 from the remaining 3 and 1 — but 3 + 1 = 4 uses them up neatly.

2. 2

   Solution A: 6 × (3 + 1) = 24, and the 4 is still unused — so that one fails the 'each exactly once' rule.

3. 3

   Try division instead: 3 ÷ 4 = 0.75, so 1 − 3 ÷ 4 = 0.25.

4. 4

   Then 6 ÷ 0.25 = 24, using 6, 1, 3 and 4 exactly once.

Try these next

• Make 24 from 8, 8, 3, 3
• Make 24 from 5, 5, 5, 1
• Try the weekly sprint in your dashboard