Every so often, it’s refreshing to step back from heavyweight issues like tort reform and the perils of offshore manufacturing, and look at something lighter but still interesting to us technical folks. And so we turn to retro math. Those of us who spent our college days in engineering and science classes before electronic calculators did math with slides and beads; that is, with slide rules and, in Asia, abacuses. Most people thought both disappeared with the advent of the electronic calculator but, much as Mark Twain is said to have remarked, "reports of their demise have been greatly exaggerated."

Walter Shawlee, of Kelowna, British Columbia, is only one of a group of slide rule aficionados but, according to Pui-Wing Tam, he’s referred to as "Mr. Slide Rule," and may have the most extensive collection on the planet. Writing in The Wall Street Journal recently, Pui-Wing reports that Shawlee taps a network of international contacts to buy and sell these venerable mathematical instruments. At any one time, he may have 3,000 slide rules in stock, many in mint condition and in their original boxes, and others that he has painstakingly restored.

Some teachers are reintroducing slide rules in their classrooms, Pui-Wing says, arguing that they foster more complex thought processes than electronic calculators. Joseph Pasquale, Ph.D., a professor of computer science and engineering at the University of California—San Diego, launched a freshman seminar on slide rules in January. "I always thought we lost something when we stopped using slide rules," he says. "They’re so much more an extension of your mind than a replacement."

The abacus first came to Japan from China about 500 years ago, and sustained industrial and economic development in Japan after World War II. Four years ago, this "traditional computer" was enjoying a strong resurgence of interest in Japan, according to Nishimura Kunio. Writing in Look Japan, Kunio said the abacus was getting fresh attention because it is said to excel at teaching calculation mechanisms and developing confidence in handling figures.

Learning the abacus is also said to help children get ahead educationally, Kunio noted, because children come to visualize the abacus in their minds, which helps them to master mental arithmetic and improves their logical thinking and concentration. "I was an abacus student myself," said Busakorn Hongsyok, an international relations coordinator for the town of Yokota-Cho, Shimane-ken prefecture, Japan, "and I can vouch for the way it teaches calculation mechanisms and develops confidence in handling figures."

The slide rule passed the calculation torch when the HP-35 hit the market on July 1, 1972. But Pasquale speaks for the enduring value of both it and the abacus when he says they extend your mind; they don’t replace it. And you never have to replace the batteries.