Quotes Gauss: had "positive, negative and imaginary (or worse still, impossible) unity, been given the names say, of direct, inverse and lateral unity, there would hardly have been any scope for such obscurity." I like that! Lateral numbers, like "throwing a lateral" in American football. It's too bad though that that only refers to addition; for multiplying you might talk about stretchy and twisty numbers instead.
"An Imaginary Tale: The Story of √-1" by Paul J. Nahin is delightful. (If you liked this and want more.)<p><a href="http://press.princeton.edu/titles/9259.html" rel="nofollow">http://press.princeton.edu/titles/9259.html</a>
And the story continues -- <a href="https://en.wikipedia.org/wiki/Clifford_algebra" rel="nofollow">https://en.wikipedia.org/wiki/Clifford_algebra</a>