Online Museum Collections in the Mathematics Classroom – Slide Rules and Logarithmic Calculations

Classroom Application #4: Slide Rules and Logarithmic Calculations

Keuffel & Esser Log Log Duplex slide rule, model 4092-3, ca 1936, Smithsonian Institution negative number 85-7411.

Slide rules are popular and readily available objects to bring into the classroom, where they may engage students in the visual experience of problem-solving, illustrate the connections between mathematics and real-life problems, and increase students' appreciation for history. The Wikipedia article gives enough information to get started; several websites offer more extensive primers on how to operate slide rules, including the Oughtred Society and the 1929 manual Teach Yourself the Slide Rule by Burns Snodgrass, formatted for the web by collector Ron Manley. The online version of Cliff Stoll's May 2006 article in Scientific American, “When Slide Rules Ruled,” included printable scales and instructions for making a paper linear slide rule. Vintage slide rules, some never removed from their original packaging, are constantly available on auction sites such as eBay, ranging from a few dollars for common, mass-produced models, to hundreds of dollars for rare, museum-quality examples. The easiest way to procure enough slide rules for an entire class, though, is to take advantage of the Loaner Program offered by Mike Konshak's online International Slide Rule Museum.