Ah, math. It’s why I became an English major. But now math is spinning back around and haunting me in the form of my fifth grader. Last night, I found myself dealing with how to multiply fractions as ...

This Design Idea presents a method for fast integer multiplying and multiplying by fractions. What can you do when you lack access to a hardware multiplier or MAC (multiply/accumulate) function and ...

“Who would draw a picture to divide 2/3 by 3/4?” asked Marina Ratner, a professor emerita of mathematics at the University of California at Berkeley, in a recent Wall Street Journal opinion piece.

Numberphile revived an ancient multiplication trick—halves and doubles—also called Egyptian or Russian math, where you repeatedly halve one number and double the other. After crossing out rows with ...