In the following examples the first two lines are the multiplicand and multiplier; and the number of decimals to be retained will be seen from the results.

·447161833·1662483·4641016
3·77192141·41421361732·508
37719214033166248346410160
8161744 631241418052371 
150876863316625346410160
15087681326650242487112
2640343316610392305
377213266692820
2263663173205
38332771
30106001·58373
1·68665912
46·90415

Exercises may be got from article (143).

155. With regard to division, take any two numbers, for example, 16·80437921 and 3·142, and divide the first by the second, as far as any required number of decimal places, for example, five. This gives the following:

3·142)16·80437921(5·34830
15·710
1·0943
9426
15177
(A) 12568
260926099
251425136
959632
949426
12061

Now cut off by a vertical line, as in (153), all the figures which come on the right of the first figure 2, in the last remainder 2061. As in multiplication, we may obtain all that is on the left of the vertical line by an abbreviated method, as represented at (A). After what has been said on multiplication, it is useless to go further into the detail; the following rule will be sufficient: To divide one decimal by another, retaining only n places: Proceed one step in the ordinary division, and determine, by (150), in what place is the quotient so obtained; proceed in the ordinary way, until the number of figures remaining to be found in the quotient is less than the number of figures in the divisor: if this should be already the case, proceed no further in the ordinary way. Instead of annexing a figure or cipher to the remainder, cut off a figure from the divisor, and proceed one step with this curtailed divisor as usual, remembering, however, in multiplying this divisor, to carry the nearest ten, as in (154), from the figure which was struck off; repeat this, striking off another figure of the divisor, and so on, until no figures are left. Since we know from the beginning in what place the first figure of the quotient is, and also how many decimals are required, we can tell from the beginning how many figures there will be in the whole quotient. If the divisor contain more figures than the quotient, it will be unnecessary to use them: and they may be rejected, the rest being corrected as in (151): if there be ciphers at the beginning of the divisor, if it be, for example,

·003178, since this is ·3178 ,
100

divide by ·3178 in the usual way, and afterwards multiply the quotient by 100, or remove the decimal point two places to the right. If, therefore, six decimals be required, eight places must be taken in dividing by ·3178, for an obvious reason. In finding the last figure of the quotient, the nearest should be taken, as in the second of the subjoined examples.

Places required,  2 8
Divisor,·41432 3·1415927
Dividend,673·1489 2·71828180
41432 2·51327416
258828 20500764
248592 18849556
10237[21]1651208
8286 1570796
1951 80412
1657 62832
294 17580
290 15708
4 1872
4 1571
0 301
283
18
19
Quotient,1624·71 ·86525596