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Number Sequence
About Number Sequence
Find the missing number in the sequence. This free online game is part of our brain training collection and is designed for players of all ages.
- Difficulty: medium
- Average play time: 3 minutes
- No download or signup required
- Works on desktop and mobile devices
How to Play Number Sequence
Find the rule behind the sequence of numbers and enter the next value. Rules include addition, multiplication, and more.
Tip: Calculate the difference between consecutive numbers to spot the pattern.
💡 Number Sequence Strategy
- Write the gaps first. Subtract each number from the one after it. If those differences are constant you have an arithmetic run, and you are done in one step.
- If the gaps vary, take the gaps of the gaps. A constant second difference means the sequence is squared-based — 1, 4, 9, 16 and its cousins hide here.
- Try dividing when numbers grow fast. Anything doubling, tripling, or growing steeply is usually multiplicative rather than additive.
- Watch for two interleaved runs. Sequences like 2, 10, 4, 20, 6 are two simple patterns zipped together; read every other term.
- Check the primes and the Fibonacci run. When nothing else fits, 2·3·5·7·11 or 1·1·2·3·5·8 often does.
🧠 What Number Sequence Builds
Finding the rule behind a run of numbers is inductive reasoning — going from examples to the law that produced them — and it is a different muscle from calculating. The arithmetic involved stays deliberately light so that the challenge lives in the noticing, not in the sums. It is a strong daily exercise precisely because each puzzle takes under a minute once the rule clicks.