missing number
Gap in sequence
A missing number is an unknown value in a mathematical sequence or equation that must be determined: Find the missing number: 2, 4, __, 8.
Common in elementary math exercises and aptitude tests, where patterns or relationships reveal the answer.
Also used loosely for any gap in a numerical series—a missing page number, a skipped entry in a list.
- puzzleChallenge testing ingenuity
- logic puzzleProblem solved by deduction
- sequenceOrdered succession of elements
- blankWithout marks or content
- fill in the blankSupply omitted information
gap · solve · figure out · pattern · riddle · brain teaser · series · next in line · unknown · hidden · guess · fill · spot · digit · clue · logic · brain · test
- brain gamesbrainteasers, brain teasers, logic puzzles, puzzles, crossword puzzles
- number puzzlessudoku, magic square, arithmetic puzzle, magic squares, multiplication table
- intelligence problemsIQ tests, brain teasers, logic puzzles, aptitude tests, analogies
- variablesvariable, unknown, x, y, placeholder
- puzzlespuzzles, sudoku, jigsaw puzzle, puzzle cube, crossword