Missing Number

Find the pattern and fill in the number missing from the middle.

How to play

A sequence of numbers has one gap somewhere in the middle rather than at the end. Work out the rule from the numbers you can see, then supply the missing value.

• The missing number can be anywhere in the sequence, not just at the end.
• Use the numbers on both sides of the gap to confirm the rule.
• No paper or calculator — do it in your head.
• Difficulty ramps up automatically as you answer correctly.

Why this matters

Interpolating a mid-sequence gap is harder than extending a series forward because you can't just extrapolate the last step — it mirrors how Woodcock–Johnson's fluid reasoning cluster tests rule application from partial, non-terminal evidence. Read more about the Woodcock–Johnson Tests of Cognitive Abilities.

This game trains