Johann Martin Zacharias Dase possessed one of the most extraordinary calculating minds ever recorded, paired, by his own admission, with little talent for the mathematics behind it. Born in Hamburg on 23 June 1824, he could perform feats of arithmetic that strained belief: he multiplied two twenty-digit numbers in about six minutes, two forty-digit numbers in forty minutes, and two hundred-digit numbers in roughly eight and three-quarter hours, all mentally.
In 1844 Dase turned this raw power to a classic problem and calculated pi to 200 decimal places over the course of some two months. The result, published in Crelle's Journal, was correct and stood as the most digits of pi yet computed. He did not stop there: he produced a seven-digit table of logarithms and, at the suggestion of leading mathematicians, extended a table of integer factorizations from six million up toward ten million — patient, monumental work for the era before machines.
Carl Friedrich Gauss was impressed enough to recommend that the Hamburg Academy of Sciences support Dase so he could devote himself to mathematical computation full-time. Gauss also noted, with characteristic precision, that a trained calculator with pencil and paper might have matched some of his feats in less time — yet no one doubted the strangeness of a man who carried such arithmetic entirely in his mind. Dase died in Hamburg on 11 September 1861, aged thirty-seven.
Achievements
- Computed pi to 200 decimal places (1844), published in Crelle's Journal
- Multiplied two 100-digit numbers mentally in about 8 hours 45 minutes
- Produced a seven-digit table of logarithms
- Extended a table of integer factorizations from 6,000,000 toward 9,000,000
- Praised and supported by Carl Friedrich Gauss
