What comes next? Odd one out — Maths trick for kids

The trick

Find the rule — “look at how each number changes from the one before”

1. Find the gap between neighbours. The same jump? Add it again.
2. Each number double the last? Double again. 1, 4, 9, 16? They are square numbers.
3. Odd one out: test each number — which one breaks the rule?

Use it for: Olympiad and reasoning tests, aptitude puzzles, and spotting patterns in tables.

Worked example: What comes next? 3, 7, 11, 15, ? → 19

✏️ Practice

Work it out in your head or on paper, then tap your answer — or type it and press Check. Stuck? Press “Show me how”.

🏁 Trick 11 test

20 questions. Check each answer, then go to the next one. Get 16 or more right to pass.

🏅 Sign in with Google to earn the 🧩 Pattern Spotter badge when you pass — and a certificate when you finish all 5 tricks of Part 3 · Puzzles & quick wins. You can still take the test without signing in.

🖨️ Number Pattern Puzzles Worksheet

• Worksheet set 1 (PDF)
• Worksheet set 2 (PDF)
• Worksheet set 3 (PDF)