Click here to win prizes by solving the puzzle Advent calendar.
Click here to win prizes by solving the puzzle Advent calendar.



Christmas (2020) is coming!

This year, the front page of will once again feature an Advent calendar, just like in the five previous Decembers. Behind each door, there will be a puzzle with a three digit solution. The solution to each day's puzzle forms part of a logic puzzle:
It's nearly Christmas and something terrible has happened: you've just landed in a town in the Arctic circle with a massive bag of letters for Santa, but you've lost to instructions for how to get to Santa's house near the north pole. You need to work out where he lives and deliver the letters to him before Christmas is ruined for everyone.
Due to magnetic compasses being hard to use near the north pole, you brought with you a special Advent compass. This compass has nine numbered directions. Santa has given the residents of the town clues about a sequence of directions that will lead to his house; but in order to keep his location secret from present thieves, he gave each resident two clues: one clue is true, and one clue is false.
The residents' clues will reveal to you a seqeunce of compass directions to follow. You can try out your sequences on this map.
Behind each day (except Christmas Day), there is a puzzle with a three-digit answer. Each of these answers forms part of a resident's clue. You must use these clues to work out how to find Santa's house.
Ten randomly selected people who solve all the puzzles, find Santa's house, and fill in the entry form behind the door on the 25th will win prizes!
The winners will be randomly chosen from all those who submit the entry form before the end of 2020. Each day's puzzle (and the entry form on Christmas Day) will be available from 5:00am GMT. But as the winners will be selected randomly, there's no need to get up at 5am on Christmas Day to enter!
As you solve the puzzles, your answers will be stored. To share your stored answers between multiple devices, enter your email address below the calendar and you will be emailed a magic link to visit on your other devices.
To win a prize, you must submit your entry before the end of 2020. Only one entry will be accepted per person. If you have any questions, ask them in the comments below or on Twitter.
So once December is here, get solving! Good luck and have a very merry Christmas!

Similar posts

Christmas (2019) is over
Christmas (2019) is coming!
Christmas (2018) is over
Christmas (2018) is coming!


Comments in green were written by me. Comments in blue were not written by me.
 Add a Comment 

I will only use your email address to reply to your comment (if a reply is needed).

Allowed HTML tags: <br> <a> <small> <b> <i> <s> <sup> <sub> <u> <spoiler> <ul> <ol> <li>
To prove you are not a spam bot, please type "y" then "-" then "a" then "x" then "i" then "s" in the box below (case sensitive):


Show me a random blog post

Nov 2020

Christmas (2020) is coming!

Jul 2020

Happy √3+e-2 Approximation Day!

May 2020

A surprising fact about quadrilaterals
Interesting tautologies

Mar 2020

Log-scaled axes

Feb 2020

PhD thesis, chapter ∞
PhD thesis, chapter 5
PhD thesis, chapter 4
PhD thesis, chapter 3
Inverting a matrix
PhD thesis, chapter 2

Jan 2020

PhD thesis, chapter 1
Gaussian elimination
Matrix multiplication
Christmas (2019) is over
▼ show ▼
▼ show ▼
▼ show ▼
▼ show ▼
▼ show ▼
▼ show ▼
▼ show ▼
▼ show ▼


radio 4 dates preconditioning mathsjam countdown books electromagnetic field binary european cup logs pi coins sobolev spaces data matrix multiplication sorting phd accuracy graphs javascript interpolation statistics national lottery rhombicuboctahedron christmas speed game show probability pi approximation day folding tube maps sport reuleaux polygons hannah fry golden ratio boundary element methods raspberry pi menace approximation video games pac-man captain scarlet rugby latex squares tmip geometry pythagoras final fantasy advent calendar matrix of minors people maths error bars bubble bobble mathsteroids graph theory talking maths in public nine men's morris chess games asteroids chalkdust magazine data visualisation matrix of cofactors map projections dataset wave scattering wool misleading statistics polynomials geogebra fractals tennis realhats curvature bempp python royal baby signorini conditions cross stitch martin gardner noughts and crosses go twitter world cup golden spiral hexapawn chebyshev machine learning gerry anderson php bodmas gaussian elimination manchester probability ternary royal institution computational complexity cambridge draughts sound folding paper a gamut of games plastic ratio london light logic simultaneous equations triangles quadrilaterals exponential growth frobel mathslogicbot dragon curves propositional calculus oeis flexagons stickers big internet math-off manchester science festival matt parker football pizza cutting hats matrices programming puzzles platonic solids finite element method trigonometry weather station christmas card numerical analysis inline code weak imposition estimation craft braiding london underground game of life harriss spiral determinants inverse matrices convergence reddit news arithmetic palindromes ucl the aperiodical


Show me a random blog post
▼ show ▼
© Matthew Scroggs 2012–2020