Number Sequence is a pattern-spotting puzzle: you are shown a run of numbers and have to work out the rule that links them, then supply the next number in the series. It is a great workout for logical reasoning and the kind of numerical pattern-recognition that appears in IQ and aptitude tests.
First look at the difference between each pair of numbers. If the differences are constant, it is arithmetic; if they grow, check whether each term is being multiplied. If nothing obvious appears, test whether the differences themselves form a pattern, or whether the sequence alternates between two rules.
What skills does this build?
Logical reasoning and numerical pattern recognition — useful for aptitude and IQ-style tests.
Is it free?
Yes, free to play with no sign-up.
Do I need advanced maths?
No — spotting the pattern matters far more than complex calculation.
Can I play on mobile?
Yes, on any device with a modern browser.