Author: Sean

#mathsonamug #maths pic.twitter.com/wSbBxEd9bm — Dr. Sean (@seanelvidge) January 18, 2016 I saw someone solving a Sudoku on the train this morning, which made again think about the minimum number of ‘clues’ required to solve a puzzle. It has been proven that you need at least 17 clues to have a unique, solvable, solution.

#mathsonamug #maths pic.twitter.com/qSGskpdj4j — Dr. Sean (@seanelvidge) January 15, 2016 I was out of the office today so didn’t have access to my chalkboard mug. Luckily I’ve got other mugs with maths on! This one has the Curtis MOG on it. Curtis (1976) came up with the method for playing around with the Mathieu groups. It is […]

#mathsonamug #maths #Powerball pic.twitter.com/AgkojRcT3y — Dr. Sean (@seanelvidge) January 14, 2016 Last nights Powerball lottery in the US was an incredible $1.5B! But what were the odds of winning? You need to get 5 numbers from a pot of 69 in the main draw, and then one ‘bonus’ ball, from a pot of 26. So the odds are […]

Inspired by yesterday’s rainbow #mathsonamug #maths pic.twitter.com/GGmrzyUtHB — Dr. Sean (@seanelvidge) January 13, 2016 Yesterday my (by far) most popular tweet was a picture of a rainbow. So I thought I would do a little diagram of what causes us to see a rainbow. The colours are reversed for a double rainbow because there is […]

#mathsonamug #maths pic.twitter.com/9WbMgghlfB — Dr. Sean (@seanelvidge) January 12, 2016 This is one of my favourite puzzles. It is a simple, life long game. Using exactly four 4s make as many numbers as you can. You can use the operators \(+,\,-,\,\times,\,\div,\,!,\,\mbox{^},\,.,\,\sqrt{},\Gamma\) and concatenation. You must use all four 4s. Let me start you off with […]

#mathsonamug pic.twitter.com/nnMowcsljj — Dr. Sean (@seanelvidge) January 11, 2016 This is a classic Martin Gardner puzzle. One solution is (from the Guardian): “Construct the additional squares indicated by dotted lines. Angle C is the same as the sum of angles A and D, since they are both made by cutting a square in half along […]

For Christmas I got one of those chalkboard mugs. Following the suggestion of someone in the office I wrote a maths equation on it, and tweeted it. Now I can’t stop. The only problem is a mug isn’t really a lot of space so I’ve been writing very little on the mug. Leaving the interested reader […]