Commence by setting 39 to the index, and the pointer to 1·37; bring
14·2 to the pointer; pointer to 19; 6·3 to the pointer, and read the
result 134 at the index.
It should be noted that after the first factor is set to the fixed
index, the _pointer_ is set to each of the _dividing_ factors as they
enter into the calculation, while the _dial_ is moved for each of the
_multiplying_ factors. Thus the dial is first moved (setting the first
factor to the index), then the pointer, then the dial, and so on.
_Number of Digits in the Result._—If rules are preferred to the plan of
roughly estimating the result, the general rules given on pages 21 and
25 should be employed for simple cases of multiplication and division.
For combined multiplication and division, modify the expression, if
necessary, by introducing 1’s, as already explained, and subtract the
sum of the denominator digits from the sum of numerator digits. Then
proceed by the author’s rule, as follows:—
_Always turn dial to the_ LEFT; _i.e._, _against the hands of a watch_.
_Note dial movements only; ignore those of the pointer._
_Each time 1 on dial agrees with or passes fixed index_, ADD _1 to the
above difference of digits_.
_Each time 1 on dial agrees with or passes pointer_, DEDUCT _1 from the
above difference of digits_.
Treat continued multiplication in the same way, counting the 1’s used as
denominator digits as one less than the number of multiplied factors.