WRITTEN EXERCISE In this exercise pupils should state the approximate answers orally, and these should be written down. The problems should then be solved on paper and the real result compared with the approximate one. This is one of the best checks against absurd results, and should frequently be made a subject of class drill with other written exercises. Teachers will not expect the same approximations from all pupils. 3 times 22 is a natural approximation for Ex. 1. a pound, what will 3§ lb. of steak cost? a gallon, what will 6.25 gal. of oil cost? 3. At 26 a pound, what will 6 lb. of butter cost? 4. At 12 a yard, what will 83 yd. of ribbon cost? 5. At $2.50 a yard, what will 2.8 yd. of velvet cost? 6. If 6 yd. of silk cost $6.75, what is the price per yard? 1. At 22 7. If 8 doz. men's hose cost $55, what is the price per dozen? 8. A man drives 39.6 mi. in 5 hr. What is the rate per hour? 9. If 48 doz. boys' hose cost $57.60, what is the price per dozen? 10. At 14 a gross, how many gross of buttons can be bought for $3.22 ? 11. A dealer buys 200 lb. of raisins for $19. How much do they cost a pound? 12. A dealer pays $18.83 for 7 rocking-chairs. How much does he pay for each? 13. A dealer sells 17 pails of mackerel for $40.80. What is the price per pail? 14. A man pays $1110 a year for the rent of a city house. How much does he pay a month? 15. Traveling at the rate of 47 mi. an hour, how far will a train go between 8.45 A.M. and 11.30 A.M.? 16. A grocer buys a 50-gal. barrel of Porto Rico molasses for $11.50. How much does it cost per gallon? 17. A grocer sells a half chest of tea, 140 lb. to the chest, for $19.60. What is the price per pound? 18. A merchant sold a 40-yd. piece of cloth for $45, gaining 12 a yard. How much did the piece cost him? 19. A grocer buys 12 doz. 1-lb. cans of cocoa at 43 each, and sells them at 58 each. How much does he gain? 20. A dry goods dealer sells 75 yd. of cloth for $112.50, thereby gaining $28.50. How much did it cost him per yard? 21. A grocer buys six 50-lb boxes of dried apples at 41 a pound, and sells them at 6 a pound. How much does he gain? How much 22. A salesman receives $15 a week. He works 49 weeks a year. His expenses are $396 a year. does he save a year? 23. If 15 men can do a piece of work in 4 da. 7 hr., a working day being 8 hr., how long will it take 3 men, working at the same rate? 24. Four places, A, B, C, D, are in a straight line. It is 17.42 mi. from A to B, 13.74 mi. from B to C, and 52.11 mi. from A to D. How far is it from C to D? 25. A merchant pays $38.40 for a piece of cloth. If there had been 3 yd. more in the piece, it would have cost him $42. How many yards were there in the piece? 26. Mr. A and Mr. B are in partnership, Mr. A contributing of the money and labor to run the business. If they make $6725 this year, what is the share of each? DENOMINATE NUMBERS REVIEW OF THE COMMON TABLES ORAL EXERCISE 1. How many ounces in a pound? An ounce is what part of a pound? 2. Tell the number of gills in a pint, pints in a quart, and quarts in a gallon. 3. Tell the number of inches in a foot and feet in a yard. An inch is what part of a foot? 4. Tell the number of quarts in a peck and pecks in a bushel. A peck is what part of a bushel? 5. How many seconds in a minute? minutes in an hour? hours in a day? days in a week? days in a common year? days in a leap year? What months have 30 days? Express the following as indicated: 6. 6 pt. as quarts. 7. 8 qt. as gallons. 8. 3 yd. as feet. 9. 14 da. as weeks. 10. 8 pk. as bushels. 11. 12 ft. as yards. 13. 15 pt. as quarts. 14. 4 wk. as days. 16. 32 oz. as pounds. 17. 2 qt. as pints. 12. 1 lb. as ounces. 15. 48 hr. as days. WRITTEN EXERCISE 1. Write the table of weight, ounces, pounds, tons. 2. Write the table of length, — inches, feet, yards, rods, miles. 3. Write the table of dry measure, — quarts, pecks, bushels. 4. Write the table of liquid measure, gills, pints, quarts, gallons. 151. Tables for reference. While these tables have been learned and used in primary arithmetic, they are here inserted for reference and for such review as may be necessary. 152. Table of length: 12 inches (in.) = 1 foot (ft.). 3 feet = 1 yard (yd.). 5 yards, or 16 feet = 1 rod (rd.). 320 rods, or 5280 feet = 1 mile (mi.). The hand (4 in.) is used in measuring the height of horses at the shoulder. Sailors use the fathom (6 ft.) and cable length (120 fathoms) for measuring depths, and the knot (nautical mile, 1.15 common or statute miles, or 6080.27 ft.) for distances at sea. 153. Table of square measure : 144 square inches (sq. in.) = 1 square foot (sq. ft.). 9 square feet = 1 square yard (sq. yd.). 160 square rods = 1 acre (A.). 640 acres = 1 square mile (sq. mi.). Carpenters, architects, and mechanics often write 8" for 8 in., and 5′ for 5 ft. They also use sq." and sq. for square inches and square feet. In this book both of these forms are used. 154. Table of cubic measure: 1728 cubic inches (cu. in.) = 1 cubic foot (cu. ft.). 128 cubic feet = 1 cord (ed.). A perch of stone or masonry is usually considered as 1 rd. long, 1 ft. high, and 11⁄2 ft. thick, and it contains 24 cu. ft. It varies, however, in different parts of the country. A cubic yard of earth is considered a load. The ton of 2000 lb. is sometimes called the short ton, there being a long ton of 2240 lb. which is used in some wholesale transactions in mining products. Goldsmiths still use an old table of Troy weight, but it is not of enough importance to justify teaching. In this table 24 grains (gr.) = 1 pennyweight (pwt. or dwt.). 20 penny weights = 1 ounce (oz.). 12 oz. 1 pound (lb.). The avoirdupois pound contains 7000 gr., the Troy pound 5760 gr. Therefore 1 lb. of iron is heavier than 1 lb. of gold. A carat weight, used in weighing diamonds, varies, but is commonly taken in the United States as 3.2 Troy grains. The word carat is also used in speaking of the purity of gold, meaning, "16 carats fine" meaning 14 pure gold. There is also a table of Apothecaries' weight, used by physicians and druggists in prescriptions. Its importance is too slight to justify teaching, although it is here inserted for those who may care to use it. 20 grains (gr.) = 1 scruple (sc. or ). estimating the capacity of tanks and cisterns 31.5 gal. are considered a barrel, and 2 bbl. a hogshead. There is also a table of Apothecaries' liquid measure, in which 16 fluid ounces make 1 pint. |