Christmas card 2018

Just like last year and the year before, TD and I spent some time in November this year designing a Chalkdust puzzle Christmas card.
The card looks boring at first glance, but contains 10 puzzles. By splitting the answers into pairs of digits, then drawing lines between the dots on the cover for each pair of digits (eg if an answer is 201304, draw a line from dot 20 to dot 13 and another line from dot 13 to dot 4), you will reveal a Christmas themed picture. Colouring the region of the card labelled R red or orange will make this picture even nicer.
If you want to try the card yourself, you can download this pdf. Alternatively, you can find the puzzles below and type the answers in the boxes. The answers will be automatically be split into pairs of digits, lines will be drawn between the pairs, and the red region will be coloured...
If you enjoy these puzzles, then you'll almost certainly enjoy this year's puzzle Advent calendar.

Similar posts

Christmas card 2020
Christmas card 2019
Christmas card 2017
Christmas card 2016


Comments in green were written by me. Comments in blue were not written by me.
Someone told me I would like this puzzle and they were right!
×1                 Reply
@Carmel: It's not meant to check your answers. It only shows up red if the number you enter cannot be split into valid pairs (eg the number has an odd number of digits or one of the pairs of digits is greater than 20).
The script for checking the answers doesn't work properly
Thank you Shawn!
So satisfying!
×1                 Reply
Great puzzle problems! Hint on #9: try starting with an analogous problem using smaller numbers (e.g. 3a + 10b). This helped me to see what I had to do more generally.
   ×1              Reply
 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 "i" then "n" then "t" then "e" then "g" then "e" then "r" in the box below (case sensitive):


Show me a random blog post

Jan 2021

Christmas (2020) is over
▼ show ▼
▼ show ▼
▼ show ▼
▼ show ▼
▼ show ▼
▼ show ▼
▼ show ▼
▼ show ▼
▼ show ▼


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


Show me a random blog post
▼ show ▼
© Matthew Scroggs 2012–2021