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9. How many pounds are there in barrel of pork? In 4 barrel of salt? In barrel of flour? In keg of nails?

10. What will be the value of 1 barrel of flour at $8.50

per cwt. ?

11. What will į quintal of codfish cost at $.061 per lb. ?

12. What will be the cost of 13 cwt. 18 lb. of hay at $15 per ton?

13. When flour is $10 a barrel, how many pounds can I buy for $2.80?

14. A merchant sold 3 cwt. 19 lb. 9 oz. of cheese at $.17 per lb. How much did he receive for it?

15. If a merchant buys flour at $9 per barrel and sells it at $5 per cental, how much will be his profit on the sale of 15 barrels?

16. How many barrels of salt are there in 275000 lb. ?

17. If the weight of a bushel of wheat is 60 lb., how many bags that hold 2 bu. each will be required to carry away 3 T. 4 cwt. 20 lb. of wheat?

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272. Troy Weight is used in weighing gold, silver, and jewels.

TABLE.
24 Grains (gr.) = 1 Pennyweight

pwt.
20 Pennyweights 1 Ounce.
12 ounces
1 Pound.

lb.

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1. In weighing diamonds, pearls, and other jewels, the unit commonly employed is the carat, which is equal to 4 grains.

2. The term carat is also used to express the fineness of gold, and means a part. Thus, gold that is 18 carats fine is i gold and a clloy.

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273. Apothecaries' Weight is used by apothecaries and physicians in weighing medicines.

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TABLE.

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1. In writing prescriptions, physicians express the number in Roman characters, using j instead of i final. They also write the symbol first; thus: Zv, 3v, Dij.

2. Medicines are bought and sold in large quantities by Avoirdupois Weight. 1 lb. Avoirdupois = 7000 gr. 1 lb.

S

Apothecaries' : 437) gr. 1 oz.

= 480 gr.

}

5760 gr.

1 oz.

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1. How many grains are there in 3 pwt.? In 5 pwt. ?
2. How many pennyweights are there in 5 oz.? In 7 oz. ?
3. How many grains are there in 7 oz. 5 pwt. 18 gr.?
4. Express 3456 grains Troy in higher units.

5. What will be the value of an ornament weighing 2 oz. 15 pwt., at $1.35 per pwt. ?

6. How many spoons, weighing 5 ounces each, can be made from 3 lb. 5 oz. of silver ?

7. How many powders, of 5 grains each, can be made from 5 oz. 7 dr. of quinine ?

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274. The following are the ordinary divisions of time:

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1. În most business computations 30 days are considered a month, and 12 months a year. For many purposes 4 weeks constitute a month.

2. The common year contains 52 weeks and 1 day, the leap year 52 weeks and 2 days. Hence, commonly, each year begins one day later in the week, but the year succeeding leap year begins two days later.

3. The time required for the earth to revolve around the sun is one year, which is 365 da. 5 hr. 48 min. 49.7 sec., or very nearly 365 days. Instead of reckoning this part of a day each year, it is disregarded, and an addition made when this would amount to one day, which would be very nearly every fourth year. This addition of one day is made to the month of February. Since the part of a day that is disregarded when 365 days are considered as a year, is a little less than one-quarter of a day, the addition of one day every fourth year is a little too much, and, to correct this excess, addition is made to only every fourth centennial year. With this correction the error does not amount to much more than a day in 4000 years. Therefore,

Centennial years whose number is exactly divisible by 400, and other years whose number is exactly divisible by 4, are Leap Years.

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The year begins with the month of January, and ends with the month of December.

The months, their names and the number of days in each, are as follows:

January, 31 da... Jan. July, 31 da. July.
February, 28 or 29 da. Feb. August, 31 da. Aug.
March, 31 da. Mar. September, 30 da.

Sept.
April, 30 da. Apr. October, 31 da. Oct.
May,

31 da. May. November, 30 da. Nov. June, 30 da. June. December, 31 da. Dec.

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EXERCISES.

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1. How many seconds are there in 5 minutes? In 6 min. ? 2. How many minutes are there in 1 hour? In 1 hr.?

3. How many days are there in 4 weeks? In 5 wk.? In 8 wk.? In 10 wk.?

4. How many hours are there in 1 day? In } da.?
5. How many days are there in } year? In į month?
6. What part of an hour are 30 minutes ? 15 min. ?

7. How many hours are there in 90 minutes? In 120 min.? In 240 min. ?

8. How many seconds are there in 5 hr. 15 min. 12 sec. ?
9. How many seconds are there in 6 hr. 27 min. 38 sec. ?
10. Express in units of higher orders 48695 sec.
11. Express in units of higher orders 38497 sec.
12. How many minutes are there in 5 yr. of 365 da. each?
13. How many days are there from Jan. 1st to May 1st ?
14. How many days are there from April 1st to Oct. 15th ?
15. Reduce 2 wk. 5 da. 13 hr. to hours.
16. Reduce 5 da. 10 hr. 15 min. to minutes.
17. Reduce 384600 sec. to higher denominations.
18. Reduce 15 hr. 12 min. 18 sec. to seconds.
19. Reduce 32965 min. to higher denominations.

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275. A Circle is a plane surface, bounded by a curved

line every point of which is
equally distant from a point
within called the Center.

276. The Circumfer-
ence is the line that bounds
B the circle.

277. An Arc of a circle is any part of the circumference.

278. A Degree is 360 of

the circumference of a circle. 279. The Measure of an Angle is that part of the circumference which is included between the lines which form the angle.

Each of the arcs of the circumferences ab, cd, DE, is a measure of the same angle, and therefore contains the same number of degrees; but since each degree is to of the circumference, the length of a degree must vary.

280, Circular or Angular Measure is used to measure arcs of circles and angles, in determining latitude, longitude, direction, the position of vessels at sea, etc.

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