This algorithm uses three variables ( in the computer programming sense ), each holding an eight-bit representation . "'a "'and "'b "'are initialized with the multiplicands; "'p "'accumulates the product and must be initialized to 0.
42.
Relying exclusively on the design of Poma de Ayala, the author explains the arrangement of white and black circles and interprets the use of the abacus as a board for making multiplications, in which the multiplicand is represented in the right column, the multiplier in the two central columns and the result ( product ) is shown in the left column.
43.
Find the product of the hundreds-multiplier and the multiplicand and write it down in a row call it the " hundreds-row " under the tens-row, but shifted one more column to the left . That is, the ones-digit of the hundreds-row will be in the hundreds-column; the tens-digit of the hundreds-row will be in the thousands-column; the hundreds-digit of the hundreds-row will be in the ten-thousands-column.
