“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.

The ASCII character set contains single-character symbols for common fractions such as 1/2, 1/4 and 3/4. Microsoft Word 2010 has the ability to detect when you type one of these fractions and convert ...