“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.

There are some basic properties of numbers any 3rd grader can tell you: Each number is represented by a single symbol, and followed by a single successor. Multiplication makes a number bigger; ...

Dividing Fractions: When dividing fractions, you can achieve the same result by multiplying the first fraction by the reciprocal of the second fraction. A fraction consists of a numerator and a ...