K&E slide rule with cursor.

Calculators are wonderful, especially if precision or speed are important. Most days I use mine two or three times at the least. I have no doubt that it saves me from much embarrassment, perhaps even jail, given that I’ve always been prone to silly arithmetical errors: the kind that without a calculator could lead to bounced checks and over-billed hours. Math in any shape never came easy to me. Useful as the calculator is, however, I have a special feeling for the slide rule that lies idle in a pigeon-hole in front of me.

Thank God for slide rules.

As I say, math did not come naturally to me. I could have accepted that fact and gone on to more congenial topics except for one thing: science fascinated me. And science requires math.

So I took high school algebra twice, although I passed it the first time. Passing isn’t understanding, and I wanted to understand.

In spite of the Ds I racked up, I continued to take math courses in college. Did someone inoculate me against math at birth? It just wouldn’t take with me.

Until slide rule class.

Early in slide rule, our teacher assigned us about a zillion simple equations of the a x b = c type. Again and again I lined a mark up on the top and read an answer on the bottom. A light went on.

I had always known theoretically that the expression on the left of the equal sign is supposed to equal the expression on the right. It’s one of the first things algebra teaches you. But now I knew it.

Richard Feynman had nothing to fear from me; but my math grades shot up.

Fortunately for me, popular ownership of calculators was still a few years off. If I’d owned one of the handy little devices then, I’d probably never have obtained the understanding that allows me to write php code or appreciate the elegance of equations such as Euler’s identity. I would be lost in a world in which mathematics is a major language revealing the mind of the creator.