# Puzzles

## Archive

Show me a random puzzle**Most recent collections**

#### Sunday Afternoon Maths LXVII

Coloured weightsNot Roman numerals

#### Advent calendar 2018

#### Sunday Afternoon Maths LXVI

Cryptic crossnumber #2#### Sunday Afternoon Maths LXV

Cryptic crossnumber #1Breaking Chocolate

Square and cube endings

List of all puzzles

## Tags

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

In August, I wrote about MENACE, a machine learning robot built from matchboxes which plays noughts and crosses. How many matchboxes are needed to build MENACE?