Page:Methods of Operating the Comptometer (1895).djvu/21

 The large figures show what keys to strike when adding, multiplying, computing interest, etc., etc., and the small figures which to strike when subtracting, dividing, exacting square root, figuring discounts, etc., etc.

It is obvious that where there are ciphers on the extreme right of the divisor they are disregarded except in pointing off for the remainder.

Thus, if the divisor be 4700 divide just the same as though it was 47 and stop dividing as soon as the quotient figure in the fifth place from the right in the register is obtained, and point off four places. That is, do not strike any keys for the divisor on the two right hand columns of the machine.

The figure in the next column to the left is always a check on the accuracy of the work. If you have struck the keys five times and the figure in the next column to the left is 4, you have struck them once too much, so push back the cut off next above the keys struck and add the divisor once.

In using large divisors, especially where high decimals are used, set the dividend on the left of the machine, so that it can be carried out decimally if desired.

Where either the divisor or dividend, or both, are decimals, set the dividend on the left of the machine, and if there be one more place to the right of the point in the dividend than there are to the left of the point in the divisor turn down the second pointer from the left of the machine, if two more turn the third pointer, etc., then proceed to divide, and the decimal point in the quotient will be where the pointer is turned down. If there is one more place to the left of the point in the divisor than in the dividend, the decimal point in quotient is to the left of the highest hole of the register.

If two more places to the left of the point in the divisor than in the dividend, the point is one place to the left of the highest hole of the register, etc. etc.