Advent calendar 2018

20 December

Today's number is the sum of all the numbers less than 40 that are not factors of 40.


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Advent calendar 2019

Sunday Afternoon Maths LXVII

Coloured weights
Not Roman numerals

Advent calendar 2018

Sunday Afternoon Maths LXVI

Cryptic crossnumber #2

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


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