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Napier's bones is an abacus created by John
Napier for calculation of products and quotients of
numbers that was based on Arab mathematics and lattice
multiplication used by Matrakci Nasuh in the Umdetul
Hisab[1] and Fibonacci writing in the Liber Abaci. Also
called Rabdology (from Greek ῥάβδoς [r(h)abdos], "rod" and
λογία [logia], "study"). Napier published his version of
rods in a work printed in Edinburgh, Scotland, at the end
of 1617 entitled Rabdologiæ. Using the multiplication
tables embedded in the rods, multiplication can be reduced
to addition operations and division to subtractions.
(Wikipedia) To multiply a multidigit number by a multidigit number, calculate partial products and add: Example: 874 x 73 = 874 x 70 + 874
x 3
874 x 7 = 6118add 874 x 70 = 61180 and 874 x 3 = +2622 _________ result: 63802 