LIGHTNING CALCULATOR: A New, Readable, and Valuable Book, CONTAINING THREE NEW PROCESSES OF ADDITION, FOUR NEW FORMS OF MULTIPLICATION, RAPID PROCESSES OF SQUARING AND CUBING, SUBTRACTION AND DIVISION, HIS IMPROVED FORM OF INTEREST, AND VALU- ABLE INFORMATION IN BOOK-KEEPING; TOGETHER WITH A HISTORY OF HIS REMfARKA.BLE LIFE, HIS WONDERFUL DISCOVE1RTIES IN NUMBERS, HIS AMUSING AND INSTRUCTIVE PARLOR FEATS, ETC., WITH HIS AUTOGRAPH. JUST ISSITED BY PROFESSOR HUTCHINGS. New York: CLARRY & REILLEY, PRINTERS AND ENGRAVERS, Nos. 12 & 14 SPRUCE STREET. 1867. |
WM. S. HUTCHINGS. |
TO Rapid and Accurate Computation, BY PROFESSOR HUTCHINGS, THE MATHEMATICAL PHENOMENON AND LIGHTNING CALCULATOR. P R E F A C E. |
which put the reader at once in possession of all the means which will enable him, with some practice, to acquire the same expeditious way of computing numbers most accurately, of which he may have seen an example at Barnum's American Museum.
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ten times; and you will discover more ease and rapidity in your computation thanl you have ever before enjoyed:
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that, after adding up the columns in the two books, the sum-total differs. Now, when such is the case, and the book-keeper wishes to ascertain whether the mistake has been made in the computation or in the extension of the single counts, he has but to subtract the lesser sum total from the larger, and divide by 9. If there be a remainder, the mistake is made in the computation; if not, it lies in the extension of the single counts, which then must be compared. For instance:
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EDWARD EVERETT.
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