4.2 THOMAS FULLER AND HIS AFRICAN MATHEMATICAL EDUCATION
Item 33 in 'Have you read?' contains brief information on the calculating prodigy Thomas Fuller (1710–1790), born in Africa and brought as a slave to the USA in 1724. John Fauvel (Open University, England) was so kind as to track the source of Rouse Ball's article (item 33): E.W.Scripture, Arithmetical prodigies, American Journal of Psychology, Vol.IV, 1891, pp.1-59. Scripture gives the following information (p.3):
"Thomas Fuller, known as the Virginia Calculator, was stolen from his native Africa at the age of fourteen and sold to a planter. When he was about seventy years old, 'two gentlemen, natives of Pennsylvania, viz., William Hartshorne and Samuel Coates, men of probity and respectable characters, having heard, in travelling through the neighborhood in which the slave lived, of his extraordinary powers in arithmetic, sent for him and had their curiosity sufficiently gratified by the answers which he gave to the following questions: First, Upon being asked how many seconds there were in a year and a half, he answered in about two minutes, 47,304,000. Second: On being asked how many seconds a man has lived who is 70 years, 17 days and 12 hours old, he answered in a minute and a half 2,210,500,800. One of the gentlemen who employed himself with his pen in making these calculations told him he was wrong, and the sum was not so great as he had said — upon which the old man hastily replied: stop, master, you forget the leap year. On adding the amount of the seconds of the leap years the amount of the whole in both their sums agreed exactly' [American Museum, Vol.V, 62, Phila., 1799].
Another question was asked and satisfactorily answered. Before two other gentlemen he gave the amount of nine figures multiplied by nine…In 1790 he died at the age of 80 years, having never learned to read or write, in spite of his extraordinary power of calculation." Fuller could find also the sum of geometrical progressions [F.D.Mitchell, Mathematical prodigies, American Journal of Psychology, Vol. XVIII, 1907, p.62]. It would be interesting to search for elements of the rich traditional African mathematical education Thomas Fuller had passed through before being sold as a slave to the USA (editors).
Who Was "The African Calculator?"
"The African Calculator" was Thomas Fuller (1710–1790), a Virginia slave who could neither read nor write, but who could quickly solve complex math problems in his head. He was once asked how many seconds a man had lived if he was 70 years, 17 days, and 12 hours old. It took Fuller only a minute and a half of mental arithmetic to answer: 2,210,500,800 seconds. One of his questioners laboriously worked out the calculation with pencil and paper, told Fuller he was wrong, and triumphantly gave another answer. In response, Fuller simply said, "You forgot the leap years."
