Posavec’s latest creation, “Multiplication Waterfall,” updates her previous work, “11 x,” and turns it into a browser-based tool that anyone can use to distill beauty out of times-tables.

Automatic Arithmetic: a New System for Multiplication and Division without Mental Labour and without the Use of Logarithms. By John Sawyer, Public Accountant. (London: George Bell and Sons, 1878.) ...

The takeaway from [Alan]’s adventures in arithmetic is that division on an AVR is slow. Not very surprising after you realize the AVR doesn’t have a division instruction.