# Advent calendar 2018

## 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

multiplication crossnumbers area doubling factorials proportion dates means advent logic symmetry menace geometry dodecagons square numbers 2d shapes pascal's triangle differentiation digits taxicab geometry books integration balancing chocolate square roots mean ave christmas perimeter quadratics sequences cube numbers regular shapes star numbers circles functions money partitions cards indices colouring chalkdust crossnumber rugby clocks division number algebra trigonometry sums cryptic clues volume perfect numbers calculus probability irreducible numbers remainders sum to infinity games arrows squares speed dice sport cryptic crossnumbers angles bases scales ellipses fractions percentages shape triangles crosswords factors floors complex numbers chess people maths addition parabolas multiples grids integers time shapes lines probabilty planes unit fractions 3d shapes wordplay routes numbers folding tube maps hexagons prime numbers graphs coordinates surds palindromes spheres polygons coins rectangles odd numbers averages triangle numbers## 1 December

There are 5 ways to write 4 as the sum of 1s and 2s:

- 1+1+1+1
- 2+1+1
- 1+2+1
- 1+1+2
- 2+2

Today's number is the number of ways you can write 12 as the sum of 1s and 2s.