Click here to win prizes by solving the puzzle Advent calendar.
Click here to win prizes by solving the puzzle Advent calendar.


Advent calendar 2015

19 December

1 = 1/2 + 1/4 + 1/8 + 1/16 + 1/16. This is the sum of 5 unit fractions (the numerators are 1).
In how many different ways can 1 be written as the sum of 5 unit fractions? (the same fractions in a different order are considered the same sum.)


Show me a random puzzle
 Most recent collections 

Sunday Afternoon Maths LXVII

Coloured weights
Not Roman numerals

Advent calendar 2018

Sunday Afternoon Maths LXVI

Cryptic crossnumber #2

Sunday Afternoon Maths LXV

Cryptic crossnumber #1
Breaking Chocolate
Square and cube endings

List of all puzzles


probability squares complex numbers multiples coordinates christmas palindromes advent sequences functions averages games bases integration star numbers time chocolate unit fractions differentiation perimeter doubling sum to infinity coins means quadratics planes crossnumbers symmetry triangle numbers digits remainders irreducible numbers speed volume taxicab geometry folding tube maps 3d shapes regular shapes indices shape percentages triangles dates shapes polygons money division grids area surds graphs cryptic clues cards lines odd numbers trigonometry factors logic books probabilty crosswords number fractions circles cube numbers parabolas rugby ave floors numbers prime numbers geometry pascal's triangle routes spheres algebra addition chess angles scales calculus 2d shapes menace clocks dodecagons perfect numbers mean rectangles factorials arrows dice colouring chalkdust crossnumber square roots hexagons sport sums wordplay ellipses balancing proportion square numbers partitions multiplication people maths cryptic crossnumbers integers


Show me a random puzzle
▼ show ▼
© Matthew Scroggs 2012–2019