After a successful edition in 2022, the editors of New Scientist are creating another Mathematics Calendar this year. With every day a mathematical fact, extraordinary proof, crazy thought experiment or wondrous mathematician. Why was our current number system once banned? How come you are almost always in the longest queue? Why are manhole covers round? And how did the '=' originate? Besides surprising facts, the calendar is packed with spicy puzzles to sink your teeth into.

Dutch.