In 1972 microprocessors hit the market as the key components of the first handheld electronic calculator. The nameplate read simply "Hewlett Packard" and the device could perform logarithmic and trigonometric functions.

It sold for $395, which in those days represented several weeks pay for a young engineer. But it was a huge success and within three years the K & E Company, manufacturer of slide rules and perhaps the biggest direct competitor, shipped the last of its mathematical magic wands. Slide rules had been the gold standard of manual calculators for 400 years, but they were blown out of the water by a battery-powered chunk of plastic with an electronic chip at its heart.

Like all the rest of the emerging electronic technology devices, the first portable electronic calculators stood on the shoulders of earlier technology. But their widespread availability took a lot of angst out of the process of performing calculations for designers, estimators and engineers, and the cost of the devices quickly dropped to affordability.

John Voeller, chief knowledge officer at Black & Veatch, Kansas City, says calculators shouldn’t be credited with inventing capability that wasn’t already available from mainframes and distributed computing. Extremely capable calculating computers were also doing just fine prior to microchip technology. "Imagine that calculators never went to miniaturization but simply stayed as they were. We still would have gotten a long way down the road. We were going out to 36-digit calculations at a level that was the equivalent to 64-bit computers back in 1969," Voeller says.

What did change was general availability of high-level electronic calculating power. Built on the same microchip technology that came to market in portable calculators, it expanded as personal computers proliferated.

Ease of use and availability continues to increase. Sophisticated and accessible calculation programs are scattered across the Web and are as accessible as a browser. One company rooted in the early years of personal computing, MathSoft, Cambridge, Mass., now offers server-based products that not only let companies manage and standardize calculation functions, but record operations and the provenance of their assumptions.