2 December

Today's number is the area of the largest dodecagon that it's possible to fit inside a circle with area \(\displaystyle\frac{172\pi}3\).

Show answer

Cube multiples

Six different (strictly) positive integers are written on the faces of a cube. The sum of the numbers on any two adjacent faces is a multiple of 6.
What is the smallest possible sum of the six numbers?

Show answer & extension


Draw a regular polygon. Connect all its vertices to every other vertex. For example, if you picked a pentagon or a hexagon, the result would look as follows:
Colour the regions of your shape so that no two regions which share an edge are the same colour. (Regions which only meet at one point can be the same colour.)
What is the least number of colours which this can be done with?

Show answer & extension


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


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


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