add-a-coin-2 Published 27 December 2016 at 953 × 467 in Forget a new £1 coin, we need a £1.23 coin ← Previous Next → Average number of coins expected as change if you add a new coin of a certain value Jigsaw Jigsaw is a talented chess player and fervent climber. All articles by Jigsaw More from ChalkdustThings to makePlatonic shapes from tube maps, flexagons, and more mathematical craftWhat’s hot and what’s notOptimal Pac-ManGhostbusting with graph theoryReinventing 2DWhat a difference a matrix makesYour social networksHow similar are you to your friends?Art meets maths