21 December

This year, I posted instructions for making a dodecahedron and a stellated rhombicuboctahedron.
To get today's number, multiply the number of modules needed to make a dodecahedron by half the number of tube maps used to make a stellated rhombicuboctahedron.

Show answer

Folding tube maps

Back in 2012, I posted instructions for folding a tetrahedron from tube maps. When tube maps are used, the sides of the tetrahedron are not quite equal. What ratio would the rectangular maps need to be in to give a regular tetrahedron?

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


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


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