21. How do we find difference in longitude when difference of time is given? How find difference of time when difference in longitude is given?

22. What is standard time? What are the names of the four time belts? In passing west into a time belt, how does the traveller set his watch? in travelling east?

23. How do we find length when area and breadth are given ?

24. How do we find length when volume, thickness, and width are given?

25. What are the dimensions of a rectangular solid? 26. Define cancellation, even number, odd number, prime number, composite.

27. When are numbers prime to each other?

28. How many cubic feet in a cord of wood or stone? How long, wide, and high is a cord of wood? What is a cord foot?

29. For what is board measure used? What is a board foot?

Give rule for finding board feet.

30. How do we find the capacity of bins ? cisterns?

THE METRIC SYSTEM.

LINEAR MEASURE.

193. The standard unit of Linear Measure in the Metric System is the Meter. It is determined by taking one tenmillionth part of the distance from the earth's equator to either of its poles, measured on a meridian. It is equal to 39.37 inches.

QUESTIONS.

194. 1. What denomination in the English linear measure is most nearly like the meter?

2. Draw a line one meter long.

3. Hold your hands one meter apart.

4. A meter is about how many feet long?

5. How many meters long is your schoolroom?

High?

6. About how many meters in a rod?

Wide ?

HOW THE TABLE IS MADE.

195. Divide a meter into ten equal parts. One of these parts is a Decimeter. Dec is a Latin stem meaning tenth. About how many inches long is a decimeter ? Show with your hands the length of a decimeter. What part of a meter is a decimeter?

196. Divide a decimeter into ten equal parts. One of these parts is a Centimeter. Cent is a Latin stem meaning hundredth. What part of an inch is a centimeter ? Show its length. How many centimeters in one meter?

part of a meter is a centimeter ?

What

197. Divide a centimeter into ten equal parts. One of these parts is a Millimeter. Mill is a Latin stem meaning thousandth. What part of a meter is a millimeter? How many millimeters in a meter? What part of an inch is a millimeter?

198. Ten meters make Greek steam meaning ten. meter? How many feet? is your schoolroom?

one Dekameter. Deka is a How many rods in a dekaHow many dekameters long

199. Ten dekameters make one Hektometer. Hekto is a Greek stem meaning hundred. How many meters in one hektometer? How many feet long is a hektometer?

200. Ten hektometers make one Kilometer. Kilo is a Greek stem meaning thousand. How many meters in one kilometer? How many feet? What part of a mile?

201. Ten kilometers make one Myriameter. Myria is a Greek stem meaning ten-thousand. How many meters in one myriameter? How many feet? How many miles?

202. These statements may be combined in the following table:

10 Millimeters (mm.) 1 Centimeter (cm.)

=

1 Decimeter (dm.)

=

=

1 Meter (m.)

.3937+ in. 3.937+ in. 39.37+

in.

=

=

1 Dekameter (Dm.)

1 Hektometer (Hm.)

1 Kilometer (Km.)

1 Myriameter (Mm.) = 6.213+ mi.

204. The following series of numbers read from the top downward is reduction ascending; read from the bottom upward is reduction descending. All metric numbers may be reduced in this way.

QUESTIONS.

205. 1. How can a metric number be reduced to higher denominations? To lower?

2. Reduce 12345678 mm. to cm.; to dm.; to m.; to Dm.; to Hm.; to Km.; to Mm.

3. Reduce 9.6538714 Mm. to Km.; to Hm.; to Dm.; to m.; to dm.; to cm. ; to mm.

4. Reduce 7 Mm. to lower denominations.

5. Reduce 7 mm. to higher denominations.

6. Reduce 6307.1 m. to Km.; to cm.

7. Reduce 31 meters to inches.

8. Write 2 Mm. as meters; 7 Km.; 6 Hm.; 8 Dm.; 5 m. 3 dm.; 2 cm. ; 9 mm.

9. Reduce 1 Mm. to feet.

Write them all as one number.

10. Write 7 Mm. and 6 mm. in one number, as meters. Reduce it to higher denominations; to lower.

11. Reduce .075 Km. to cm.

12. Reduce 8 Dm. and 6 m. to Mm.; to mm.

13. Write 75 Km. and 62 dm. in one number as meters; as cm.; as Mm.

14. State the value of each figure in 30769.543 M.

15. A ship sails 100 Mm. in one day. How many miles does it sail?

16. Give the table of Metric Linear Measure.

17. Name the standard unit.

18. How is it determined?

19. What is the scale of the Metric system?

20. Name in order the Latin and Greek stems used in the table.

SURFACE MEASURE.

206. The standard unit of surface measure is the Are (pronounced like the English air).

The Are is a square whose side is one dekameter. It is therefore a Square Dekameter.

QUESTIONS.

207. 1. An are is how many meters long? Wide? 2. How many square meters does the are contain ?

3. An are is how many inches long? Feet?

4. The are is about how many rods long?

5. About how many square rods does it contain?

6. About how many ares equal one acre ?

7. How many ares does the floor of your schoolroom contain ?

8. Name all the surfaces you can think of that contain about one are.

TABLE.

208. The table of surface measure, like that of linear measure, is made by prefixing the Latin and Greek stems to the standard unit, thus:

NOTE.

- The denominations of the above table are little used, except the are, the hektare, and the centare, which are employed chiefly in measurements of land.

209. Draw a square whose side is one meter. How many square meters does it contain? It is how many