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Genaille-Lucas Multiplication Applet

Division Applet

 Genaille–Lucas rulers (also known as Genaille's rods) is an arithmetic tool invented by Henri Genaille, a French railway engineer, in 1891. The device is a variant of Napier's bones. By representing the carry graphically, the user can read off the results of simple multiplication problems directly, with no intermediate mental calculations. Example: 874 x 7 Start reading the result by the first number in the right hand column (8), and follow the triangles:              To multiply a multi-digit number by a multi-digit number, calculate partial products and add: Example: 874 x 73 = 874 x 70 + 874 x 3   874 x 7 = 6118 874 x 3 = 2622 add    :             61180                        +2622                      _________ result:             63802 Genaille-Lucas Division Applet

 Links Genaille–Lucas rulers (Wikipedia) Early Calculation (Ed Thelen) Napier's Bones, Genaille-Lucas Rulers (Georgi Dalakov) Napier's Bones and the Genaille-Lucas Rulers (Brian Borchers) Qui est Henri Genaille? Digitale Rechengeräte Rods for Multiplication and Division

Updated: 2013 May 13