THE author makes his title, “Quick and Easy Methods of Calculating”—at least, that is all that is in large print on the title-page; but the binder calls it, on the outside of the book, “The Slide-Rule ...

Logarithms are a common idea today, even though we don’t use them as often as we used to. After all, one of the major uses of logarithms is to simplify computations, and computers do that just fine ...

A regular slide rule takes advantage of the fact that you can multiply and divide by adding logarithms. Imagine having two rulers marked in inches or centimeters — it doesn’t matter (see the adjoining ...

Before there were apps for tablets and smartphones, before mathematics education software was easily installed on personal computers, before electronic calculators entered professional practice and ...

The slide rule, sometimes called a slipstick, was a type of mechanical analog computer. It was and still is, used primarily for multiplication and division, and also for functions such as roots, ...

It was the only technological tool widely and continuously used for over three centuries. For math and science geeks it was a badge of honor, nestled neatly into a plastic pocket protector along with ...

You may find this hard to believe, but there are people still alive today who once did their mathematical calculations by sliding sticks back and forth. No keypads, no batteries, no LEDs. Just sticks.

Michael Kanellos is editor at large at CNET News.com, where he covers hardware, research and development, start-ups and the tech industry overseas. Stanford University is hosting an exhibit on the 350 ...