This is the basic method of division by subtraction. Note that the registers have a slightly different usage.
Shift carriage as far to the right as it will go. Set the dividend 147 in the setting register and then transfer it into the result register by one clockwise turn of the crank handle. Note that for division the result appears in the revolution or quotient register, not the result register.
Do not forget to clear the 1 which appears in the revolution register.
Using the setting levers set the divisor in the correct decades by clearing the 1 to 0 and replacing the 47 by 12. The machine now counts how many times 12 can be subtracted from 147. The result, the quotient, will appear in the quotient register.
You now start dividing by turning counter-clockwise, subtracting from the result register which reduces down towards zero until it goes past zero and 9s appear in the highest decades. Usually this causes a bell to
The bell signal means that you have made one counter-clockwise rotation too many, which must be corrected by turning the crank handle once the opposite way to clear the 9s in the highest decades. In this example, the
bell rings at the second turn.
After correcting the over-turn by one clockwise turn, shift the carriage one place to left with the appropriate carriage movement key, and continue subtracting until the bell rings again, when you again compensate
for over-turn by one in the opposite direction.
Continue in this way until until the problem is solved when the dividend disappears completely from the result register and the quotient register shows the result of the division - 12.25.