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
 2026 

Feb 2026

Christmas (2025) is over
 2025 
▼ show ▼
 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

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

Archive

Show me a random blog post
▼ show ▼
© Matthew Scroggs 2012–2026