# 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

angles time square numbers differentiation dates complex numbers bases sums area sequences number averages taxicab geometry functions crosswords 2d shapes rectangles dodecagons palindromes folding tube maps books coins means ellipses remainders colouring regular shapes calculus grids multiples mean surds chocolate crossnumbers integration odd numbers logic parabolas perimeter chalkdust crossnumber partitions lines floors square roots probabilty ave triangles spheres polygons shapes doubling prime numbers rugby shape chess proportion sport algebra hexagons coordinates pascal's triangle probability integers symmetry star numbers division scales quadratics digits 3d shapes dice unit fractions money graphs sum to infinity christmas balancing cube numbers indices cryptic clues multiplication games menace numbers triangle numbers circles clocks speed volume cards planes arrows fractions percentages routes advent factors geometry people maths trigonometry cryptic crossnumbers factorials squares irreducible numbers wordplay addition perfect numbers## 16 December

Arrange the digits 1-9 in a 3×3 square so that the first row makes a triangle number, the second row's digits are all even, the third row's digits are all odd; the first column makes a square number, and the second column makes a cube number.
The number in the third column is today's number.

triangle | |||

all digits even | |||

all digits odd | |||

square | cube | today's number |