A rare and unusual apparatus to help teach elementary schoolchildren how to do arithmetic, invented and handmade by a German elementary school teacher. Green-painted sloped wooden box with metal hinged flaps at front and back (front flap lacking closure clasp), with metal carrying handle to top, containing within two rows of red and white enameled metal "fingers" mounted to a metal rod, mounted patent label to top of case. Some expected cracking to paint, light soiling, handling wear, overall very good. Gütersloh, Germany; circa 1920.

Wilhelm Wlecke was a German elementary school teacher from Gütersloh who believed that children who had difficulty in learning arithmetic would benefit from using their fingers to calculate, and wanted to help his students progress more easily through their curriculum. At the time, using one's fingers to add and subtract was frowned upon in school although more practically used in everyday life. He developed this finger-counting device in 1919 to help students visualize how to calculate using their fingers. In 1929, Wlecke published the concept behind his device, titled "Die Finger als Fundament des ganzen Zahlenbaues". In it, he wrote, "The clearer the visual representation, the more reliable and enduring the memory's work."

The apparatus consists of a wooden case with hinged lid and two sets of metal fingers, one in red enamel and one in white, which are mounted on a metal rod with hinges. The fingers could be moved individually to assist in making various calculations. The apparatus could be placed on a teacher's desk to assist the whole class at once in solving problems. The fingers faced the students, and the teacher could operate them from the back of the case via a hinged back to the case and levers on the back of each finger, flipping them up or down as necessary. One "hand" or set of fingers could represent numbers 1 through 10, while the other "hand" or set represented 10s.

This "finger calculator" has been written about and profiled, both as an educational tool and as a functional design object, by various institutions including the Oberschlesisches Landesmuseum in Ratingen; the Deutsches Technik Museum in Berlin; the HNF - Heinz Nixdorf MuseumsForum in Paderborn; the Schulmuseum Bremen; and the Museo Ciencia/Zientzia Museoa in Navarra, Spain. Another institution that owns a copy of the calculator is the Stadtmuseum Gütersloh, as noted by the HNF.

Wlecke obtained a German Reich patent in 1921, no. DE331979, for his calculator. According to the Heinz Nixdorf MuseumsForum, two different sizes were sold. The larger cost 32 Reichsmarks, about $7.62 cents at the time or approximately $150 today, which schools could rent for a year. Wlecke likely traveled around parts of Europe, peddling his device, as an issue of Schweizer Schule magazine from 1931 reports on a successful demonstration given by Wlecke to the Swiss city of Stans. However, according to the Oberschlesisches Landesmuseum, even though it was widely used for a brief period, it did not achieve longevity and production ceased in 1930. Its artisanal manufacture - it is believed that Wlecke handmade all of his devices - also created difficulties for its widespread use. Today, you can only find examples such as this one in museums.

Book ID: 53750

Price: $8,500.00