Number Sequence
Find the missing number in arithmetic, geometric, square and other sequences. Four difficulty levels.
Choose your answer.
1491625?
How to play
- Find the missing number and type it in.
- Sequences are built from a fixed rule — arithmetic, doubling/geometric, squares, cubes, triangular, Fibonacci-style, alternating or growing differences, primes. The rule is explained after each answer.
- Easy hides the last term; harder levels can hide one in the middle.
- Levels: Easy uses simple patterns; Hard mixes more rules; Extreme uses the hardest rules; Nightmare uses the hardest rules for 15 questions with 10 seconds each — running out of time counts as wrong.