mscroggs.co.uk

mscroggs.co.uk

blog puzzles academic talks contact subscribe ↓ ☰ ↓

Comment

Comments

Comments in green were written by me. Comments in blue were not written by me.

2024-12-19

Matt, great card this year! Problems 1 and 2 are slightly ambiguous though in that you did not specify that each digit could only be used once.

I initially thought the answers were simply 44×44 = 1936 and 99×99999999 = 9899999901, respectively ????

Dan Whitman
on /blog/112

×1

×1

Archive

Show me a random blog post

2026

May 2026

World Cup stickers 2026

Apr 2026

A new puzzle every day
Mixing Wordle with other games

Feb 2026

Christmas (2025) is over

2025

Dec 2025

Christmas card 2025

Nov 2025

Christmas (2025) is coming!

Sep 2025

The partridge puzzle

Aug 2025

TMiP 2025 puzzle hunt

Jun 2025

A nonogram alphabet

Mar 2025

How to write a crossnumber

Jan 2025

Christmas (2024) is over
Friendly squares

2024

Dec 2024

A regular expression Christmas puzzle
Christmas card 2024

Nov 2024

Christmas (2024) is coming!

Feb 2024

Jan 2024

Christmas (2023) is over

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

Tags

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

Archive

Show me a random blog post
▼ show ▼

© Matthew Scroggs 2012–2026