The Modular Method of Mahjong Keeping track of the game is an exercise in the useful arithmetic of remainders. So is reading a clock.

You may never have heard of modular arithmetic, but you use it every day without the slightest difficulty. In this system, numbers wrap around when they reach a certain size called the modulus; it ...

One of my fellow contributors here recently wrote a post about leap years and why we have them. This reminded me of modular arithmetic and the formula for calculating the day of the week for any date ...