The above-mentioned three units are used in the measurement of short distances. For greater distances a larger unit is desirable. For such purposes the kilometer, or 1000 meters, is used. It is about g of a mile. Weight The unit of weight is the gram, which is the weight of a cubic centimeter of pure water at 4° Centigrade. A decigram is one tenth of a gram. These units are used in weighing small bodies. For heavier bodies a larger unit is used, namely, the kilogram, which is 1000 grams. The kilogram is about 2.2 pounds. Volume The unit of volume is the liter, or cubic decimeter, and is equal to about 2 pints. Summary The metric units are subdivided decimally. Thus, to express .1 of a meter, .1 of a gram, and .1 of a liter, the Latin prefix deci- is used in each case. Decimeter means To of a meter; decigram ij of a gram; and deciliter id of a liter. To express .01 of a meter, gram, and liter, the Latin prefix centi- is used. Thus, centimeter means iðy of a meter; centigram means ido of a gram, etc. To express .001 of a meter, gram, and liter, the Latin prefix milli- is used, giving rise to the terms millimeter. milligram, etc. As the system is a decimal one, 10 times one unit of any denomination equals one unit of the next higher denomination. To express 10 times a meter, 10 times a gram, and 10 times a liter, the Greek prefix deca- is used in each case, so decameter means 10 meters, decagram means 10 grams, and decaliter means 10 liters. To express 100 times a meter, gram, and liter, the Greek prefix hecto- is used in each case. Thus hectometer means 100 meters; hectogram means 100 grams, etc. To express 1000 times a meter, gram, and liter, the Greek prefix kilo- is used, giving rise to the terms kilometer, kilogram, etc. Miles to kilometers 1.60935 Kilometers to miles. 0.62137 Miles to meters 1609.347 Meters to miles. 0.0006214 Yards to meters 0.91440 Meters to yards . 1.09361 Feet to meters 0.30480 Meters to feet 3.28083 Inches to centimeters . 2.54000 Centimeters to inches 0.39370 Inches to millimeters 25.40005 Millimeters to inches 0.03937 . . Area Square yards to sq. Sq. meters to sq. yd. . meters (m.) 0.83613 Sq. meters to sq. ft. Sq. ft. to sq. meters (m.2) 0.09290 Sq. cm. to sq. in. Sq. in. to sq. cm. (cm.) 6.45163 Sq. mm. to sq. in. Sq. in. to sq. (mm.).. 645.163 1.19599 10.76387 0.15500 0.00155 mm. Volume To CONVERT MULTIPLY BY Cubic yards to cu. Cu. meters to cu. yd. 1.30802 meters (m.) 0.76456 Cu. meters to cu. ft. . 35.31661 Cu. ft. to cu. meters Cu. cm. to cu. in. 0.06102 (m.). . 0.02832 Liters to cu. ft. 0.03532 Cu.in. to cu.cm. (cm.) 16.38716 Liters to cu. in. 61.02337 Cu. ft. to liters 28.31701 Liters to gallons 0.26417 Cu. in. to liters 0.01639 Gallons to liters 3.7,8543 Roman numerals are now seldom used except in date inscriptions, in numbering chapters, and upon the dials of timepieces. The letters used and some of their combinations are as follows: 1 I 10 X 2 II 20 XX 3 III 30 XXX 4 IV, or IIII 40 XL 5 V 50 L 6 VI 60 LX 7 VII 70 LXX 8 VIII 80 LXXX 9 IX 90 XC 100 C 1000 M The letters used are I, V, X, L, C, D, M. When a letter of less value is written after a letter of greater value its value is added to that of the letter of greater value, as in VI, LX, DC. When a letter of less value is written before a letter of greater value its value is taken from that of the letter of greater value, as in IX, XC, CM. A straight line placed horizontally over a letter or combination of letters has the effect of multiplying by one thousand. ORAL DRILL Read the following numbers : 1. XVI 6. XL 11. LXXXIII 16. XC 2. XVIII 7. XLII 12. LXI 17. XCIII 3. XXIV 8. XLVII 13. LIX 18. MDCC 4. XXIX 9. LX 14. LXXIX 19. MDCCCXX 5. XIX 10. LXIX 15. CXX 20. MCMXV 1. How many steps does a man take in walking a mile if he advances 30 inches at each step? 2. If a man takes 37 steps for every 100 feet that he advances, what is the length of each step ? 3. How many bushels will a bin 8 feet square and 6 feet deep hold? 4. How many bags of two bushels and a half capacity can be filled from 260 bushels ? 5. How many gallons will a tank 4 feet 8 inches by 2 feet 10 inches by 1 foot 6 inches hold ? 6. The bottom of a rectangular tank is 6 feet square. How deep must it be to hold 1000 gallons ? 7. How many cakes of soap 4 inches by 3 inches by 11 inches can be packed in a box whose inside dimensions are 2 feet, 3 feet, and 4 feet ? 8. How many cubic yards of earth must be removed in digging a cellar 36 feet long, 26 feet wide, and 8 feet deep ? 9. Find the cost of digging a cellar 42 feet long, 28 feet wide, and 6 feet 6 inches deep, at 50 cents a cubic yard. 10. What is the capacity in gallons of a rectangular tank 9 feet square and 8 feet deep? 11. At $ 1.20 a bushel what is the value of a bin of wheat 16 feet long, 8 feet wide, and 4 feet deep ? 12. What is the capacity in gallons of a rectangular tank 12 feet long, 10 feet wide, and 6 feet deep? 13. What must be the width of a lot 200 feet long if its area is one half an acre ? 14. If sound travels at the rate of 1100 feet a second, how far distant is a thunderstorm if the thunder-clap is heard 7 seconds after the lightning flash is seen ? 15. If William Cullen Bryant was born Nov. 3, 1794, how old was he June 12, 1878 ? 16. How many years have elapsed since Dec. 22, 1620? 17. If a rug 9 feet by 12 feet is laid on the floor of a room which is 11 feet by 14 feet, how many square feet of floor surface are bare ? 18. An inch of rain on a 12-acre ranch amounts to how many gallons of water? |