ARITHMETIC.
L. mo.
L. mo. L. s. d.
6x9:
100 :: 12 X 3 7 6
20
20
120
67
12
12
1440
810
9
12
12960
9720
100
12960)972000(75
90720
64800
64800
I. mo. L. mo.
Or thus, 6x9: 100 * : 111 X 3 7 6
12
40
10
0
10
405
0
0
10
9)4050
0
0
6)450
75/.
L. mo, L. mo. L. s. d.Or thus, 6 x 9 : 100 : : 12 X 3 7 6J 2 2
6 15 0
10
67 10 0
10
I lie same question by two operations.
mm d. men150 : 27: : 100100
150)2700(18 days
-miles d. milts3 : 18 : : 55
3)90(30 days.
Answer.
Boles of Practice.
(27.) By Rules of Practice are meant certain expeditious me-thods of casting up accounts: they consist of the most generalcontractions ot the rule ot three when either the lirst or thirdterm is 1.
Rule I. To find the Price of any Integer Number ofThings.
4Vhen the number is not very great, multiply the prise of 1 orthe integer, by the given number whose price is to be found, asin compoud multiplication, and the product will be the price re-quired.
It the multiplier exceed 12, it is commonly best to multiplysuccessively by its component parts, as in simple multiplication.But if the multiplier cannot be exactly produced by the multipli-cation of small numbers, find the nearest to it, eitlier greater orless, which can be so produced; th^n after having multiplied con-tinually by the component parts of this number, to or from thelast product, add or subtract the produce of so many as it is less.or greater than the given number.
Example.
What is the value of 38 cwt. at Jl. 1 Is. 4d. per cwt. ?
L.
s.
d.
1
11
4
3
4
14
0 value of 3 cwt.
12
56
8
0 value of 36 cwt.
3
2
8 -- of. 2--
Ans. 59 10 8 - of 23 cwt.
9)675 0 0
75/.
(26.) The same may be performed at two operations. Thus,take the middle term, and two of the others, both of a kind, andproceed according to the directions in the Rule of r l liree; thentake the fourth number resulting from this stating for the middleterm of the next stating, and proceed with the remaining twoterms as before.
L. L.
s.
d.
L. L. s. mo.
100 : : 3
7
6
9:56 5:: 12
10
3 4 4
33
15
0
3)225 0
10
-—
75 1. Answer.
6)337
10
0
--
56 5
Another Example.
If 100 men make 3 miles of road in 27 days, in how manydays will 150 men make 5 nnles?
men (!. men3 x 150: 27 : : 100 X 5miles 3 5 miles
450 500
27
450)13500(30 days. Answer.
When the number is very large, as many hundreds or thou-sands; multiply the price ot 1 continually by 10 till it come to thehighest denomination ; namely, twice by 10 for hundreds, thriceby 10 for thousands, &c. then multiply these several products,by their respective local digits in the given number, which lastproducts place orderly under each other, and add them togetherlor the answer, as in the following
Example.
To find the price of 7985 at 7s. 10$d.
£.
s.
d.
0
7
10$ X10
5
3
18
111
X
8
10
39
9
7
X
9
10
394
15
10
X
7
7
2763
10
10 -
7000
355
6
3 -
900
31
n
8 -
80
1
19
H
5
3152
8
21
7985
3 O
VOL. I.—NO, 15.
Rul*