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


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


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