eighty-one
Eighty plus one
Eighty-one is the cardinal number between eighty and eighty-two, written 81.
It is nine squared and the sum of the first nine odd numbers.
In many Asian cultures, eighty-one carries lucky connotations because of its mathematical properties.
grid
Logic grid puzzle
- puzzleChallenge testing ingenuity
- matrixOrdered numerical arrangement
- squaresFour-sided equal figures
- cellsBasic biological units
rows · columns · boxes · grid · solution · logic · brainteaser
mathematics
Raising to a power
- compositeMade of distinct parts
- integerNumber lacking fractions
- productManufactured item for sale
- factorizationDecomposing into multiplicative parts
odd · arithmetic · power · root
sudoku
Logic grid puzzle
cells · rows · columns · boxes · grid · solution · logic · brainteaser
exponentiation
Raising to a power
factorization · odd · arithmetic · power · root
octogenarian
Person in ninth decade
- elderlyAdvanced in age
- seniorHigher in rank
- retirementLeaving the workforce permanently
pensioner · aged · venerable · elder · mature · wisdom · experience · longevity · geriatric
cricket
Chirping legged insect
total · batting · wickets · overs · scoreboard · milestone · points