# Advent calendar 2018

## Archive

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#### 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

sport cards grids prime numbers perfect numbers clocks money factors shape functions angles chocolate dice calculus speed scales sequences means chalkdust crossnumber area cryptic crossnumbers arrows regular shapes remainders palindromes rectangles coins integers logic star numbers dates time probability symmetry multiplication 2d shapes factorials integration indices christmas dodecagons games squares proportion percentages surds shapes circles differentiation crosswords number trigonometry polygons ave algebra balancing ellipses lines rugby complex numbers square numbers cryptic clues hexagons sum to infinity numbers unit fractions books bases odd numbers routes mean addition sums spheres triangles parabolas coordinates chess irreducible numbers fractions digits pascal's triangle crossnumbers taxicab geometry planes menace people maths division doubling square roots volume floors colouring multiples folding tube maps cube numbers averages geometry 3d shapes graphs quadratics triangle numbers wordplay probabilty perimeter advent partitions## 21 December

Put the digits 1 to 9 (using each digit exactly once) in the boxes so that the sums are correct. The sums should be read left to right and top to bottom ignoring the usual order of operations. For example, 4+3×2 is 14, not 10. Today's number is the smallest number you can make using the digits in the red boxes.

+ | ÷ | = 2 | |||

× | + | - | |||

× | - | = 31 | |||

+ | + | - | |||

- | × | = 42 | |||

= 37 | = 13 | = -2 |