One day your minimalist friend is visiting, and she presents you with the numbers 2, 3, 4 and 5, and the symbols = and +, and the following tantalizing challenge:  It is possible to use each number and symbol once and only once and end up with a true equation; further, you cannot use any number or symbol not given. How can you do this?

Communicated by Samantha Bergh, who heard it from a Wisconsin math teacher, who believes he read it on a Cheerios box.

This is not a word riddle in which it matters that 4 is written four in English. It is a search for a general math equation.