mscroggs.co.uk
mscroggs.co.uk

subscribe

Comment

Comments

Comments in green were written by me. Comments in blue were not written by me.
For Day 23, I assume the 3-digit numbers are read top to bottom and left to right?

So the bottom right corner must be odd (the ones digit of an odd number) and it must be even (the ones digit of a multiple of 4)? Isn't that a contradiction if I'm understanding the problem correctly?
Dan
on /blog/69
               

Archive

Show me a random blog post
 2025 

Mar 2025

How to write a crossnumber

Jan 2025

Christmas (2024) is over
Friendly squares
 2024 
▼ show ▼
 2023 
▼ show ▼
 2022 
▼ show ▼
 2021 
▼ show ▼
 2020 
▼ show ▼
 2019 
▼ show ▼
 2018 
▼ show ▼
 2017 
▼ show ▼
 2016 
▼ show ▼
 2015 
▼ show ▼
 2014 
▼ show ▼
 2013 
▼ show ▼
 2012 
▼ show ▼

Tags

numerical analysis pascal's triangle mean matrix of cofactors geometry folding tube maps big internet math-off datasaurus dozen palindromes statistics tmip map projections zines edinburgh turtles convergence game of life guest posts noughts and crosses christmas card runge's phenomenon data harriss spiral squares sport latex advent calendar football the aperiodical live stream sobolev spaces fonts php sound pizza cutting reddit mathslogicbot probability fractals python books signorini conditions world cup bots bempp video games hexapawn cross stitch gather town platonic solids menace manchester rhombicuboctahedron speed sorting logo logs stirling numbers triangles radio 4 martin gardner kings flexagons craft friendly squares inline code youtube frobel misleading statistics matrix multiplication inverse matrices error bars nine men's morris exponential growth games raspberry pi wave scattering draughts crochet pi game show probability rugby electromagnetic field cambridge computational complexity tennis finite group gerry anderson graph theory hats preconditioning braiding fence posts reuleaux polygons geogebra regular expressions pythagoras crossnumbers programming weak imposition databet news dragon curves royal institution weather station arithmetic newcastle anscombe's quartet numbers standard deviation dates hyperbolic surfaces polynomials binary recursion pac-man final fantasy hannah fry 24 hour maths bodmas european cup crosswords folding paper curvature phd go data visualisation simultaneous equations trigonometry machine learning quadrilaterals people maths errors oeis estimation london underground puzzles asteroids dinosaurs countdown mathsteroids golden ratio a gamut of games correlation stickers wool london dataset talking maths in public mathsjam light accuracy determinants interpolation chebyshev royal baby captain scarlet chalkdust magazine ucl logic finite element method realhats pi approximation day plastic ratio bubble bobble christmas crossnumber matt parker golden spiral boundary element methods matrix of minors gaussian elimination ternary manchester science festival javascript graphs national lottery chess approximation coins propositional calculus matrices

Archive

Show me a random blog post
▼ show ▼
© Matthew Scroggs 2012–2025