Here the number of digits in the dividend is −3, and in the divisor −1. The difference is −2; but as the result is obtained with the slide to the right, this result must be increased by 1, so that the number of digits in the quotient is −2 + 1 = −1, giving the answer as 0·013. If preferred, the result can be obtained in the manner referred to when considering the multiplication of decimals. Thus, treating the above as whole numbers, we find that the result of dividing 221 by 17 = 13, since the difference in the number of digits in the factors, which is 1, is, owing to the position of the slide, increased by 1, giving 2 as the number of digits in the answer. Then by the rules for the division of decimals we know that the number of decimal places in the quotient is equal to 6 − 3 = 3, showing that a cypher is to be prefixed to the result read on the rule. As in multiplication, so in division, we have a GENERAL RULE FOR NUMBER OF DIGITS IN A QUOTIENT.—_When the first significant figure in the_ DIVISOR _is greater than that in the_ DIVIDEND_, the number of digits in the quotient is found by subtracting the digits in the divisor from those in the dividend. When the contrary is the case, 1_ IS TO BE ADDED _to this difference. When the first figures are the same, those following must be compared._ ESTIMATION OF THE FIGURES IN A QUOTIENT.—The method of roughly estimating the number of figures in a quotient needs little explanation. EX.—3·95 ÷ 5340 = 0·00074. Setting 534 on C to 3·95 on D we read under the (R.H.) index of C, the significant figures on D, which are 74. Then 3·9 ÷ 5 is about 0·8 and 0·8 ÷ 1000 gives 0·0008 as a rough estimate. EX.—0·00000285 ÷ 0·000197 = 0·01446. Regarding this as 2·85 × 10^{−6} ÷ 1·97 × 10^{−4} we divide 2·85 by 1·97 and obtain 1·446. Dividing the powers of 10 we have 10^{−6} ÷ 10^{−4} = 10^{−2}, so the decimal point is to be moved two places to the left and the answer is read as 0·01446. Another method of dividing deserves mention as of special service when dividing a number of quantities by a _constant divisor_:—Set the index of C to the divisor on D and over any dividend on D, read the quotient on C. For the division of a _constant dividend_ by a variable divisor, set the cursor to the dividend on D and bring the divisor on C successively to the cursor, reading the corresponding quotients on D under the index of C. Another method which avoids moving the slide is explained in the section on “Multiplication and Division with the Slide Inverted.” CONTINUED DIVISION, if we can so call such an expression as (3·14)/(785 × 0·00021 × 4·3 × 64·4) = 0·0688, may be worked by repeating as follows:—Set 7·85 on C to 3·14 on D, bring cursor to index of C, 2·1 on C to cursor, cursor to index, 4·3 to cursor, cursor to index, 6·44 to cursor, and under index of C read 688 on D as the significant figures of the answer.