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1. In $2.10 what figure shows the number of whole dollars? What figure shows the part of a dollar?
2. What name is given to the dot which separates the number of whole dollars from the part of a dollar?
3. How many tenths of a dollar are expressed by $.20 or by $.2?
4. Read as dollars and tenths of a dollar: $1.5; $2.5; $8.9; $125.5; $12.6; $.1;
Similarly, a number of feet and tenths of a foot, or of pounds and tenths of a pound, or of anything else may be expressed by using the decimal point.
In reading a whole number and a number of tenths the decimal point is read "and." Thus, 1.2 ft. is read "One and two tenths feet."
The place at the right next to units' place is called tenths' place. The decimal point separates these two places.
Numbers expressed by use of the decimal point are said to be written decimally.
1. If 40 yards of cloth are divided into ten equal parts, how many yards are there in one part? How many are there in seven of these parts?
Find of 40 yards.
of 40 yards.
of 30 pounds; of 50 yd.; of 1,200 ft.; of
4. Find of $20; of $100; of 120 tons; of 970 days. 5. Write decimally:
6. Find .1 of 120 in.; of 70 weeks; of 400 mi.; of 20 qt. 7. Find .7 of 90 days; of 120 minutes; of 140 ft.; of 70 tons.
8. How many tenths of a yard in two whole yards? In 3 yards? In 5 yd.? In 1 yd. and 5-tenths of a yard?
9. How many whole pounds are there in 30 tenths pounds? In 50 tenths pounds? In 20 tenths pounds?
10. Express in units and tenths: 17 tenths; 23 tenths; 81 tenths; 395 tenths.
11. Express decimally: 19 tenths; 29 tenths; 7 tenths; 175 tenths; 204 tenths.
12. Express in tenths: 2; 3; 5; 2.1; 2.3; 2.5; 23.4. 13. How many tenths of a dollar are ten times one-tenth of a dollar? How many dollars?
14. How many tenths of a dollar are ten times two-tenths of a dollar? How many dollars?
15. 10 times .1=?
16. 10 times 35 tenths =?
17. 10 times 405 tenths =?
10 times .2=?
10 times 3.5=?
10 times 40.5=?
18. How many places is the decimal point moved to the right in multiplying by 10?
19. Multiply by 10 by moving the decimal point:
.3; 7; 9; 1.1; 1.9; 20.1; 29.8; 196.7; 2,879.3.
1. How many are 3 times 5 tops? How many are Express 5 tenths decimally.
3 times 5 tenths?
2. How many
7 times 6 tenths?
are 7 times 6 hours? How many are Express the result decimally.
25. The length of about 39.4 in., called a meter, is used as a unit in the system known as the Metric or International System of weights and measures. It is the standard system of nearly all the leading civilized countries except the British Empire and the United States. It is permitted by law in the latter countries. How many inches are there in 3 meters? In 5 meters? In 10 meters? In 9 meters? In 100 meters? 26. A square is 2.4 ft. on a side. Find its perimeter. 27. A triangle is 13.7 in. on each side. Find its perimeter. 28. An ox killed and dressed is about .8 as heavy as when alive. An ox which weighs 880 lb. when alive, weighs how many pounds dressed?
1. A man bought 1 bu. each, of oats at $.40 a bushel, of wheat at $.90 a bushel, of beans at $1.20 a bushel, and of grass-seed at $3.30 a bushel; how much did he pay for all?
2. A farmer sowed 4 pieces of land and used 5.3 bu., 2.5 bu., 10.1 bu., and .8 bu. of seed respectively; how much did he sow in all?
3. When wheat is bought at 60¢ per bushel and sold at 704, what is the gain per bushel? 4. An acre of land produced 28.5 bu. of wheat. When sown with oats it produced 32.3 bu. How many more bushels of oats than wheat did it produce?
5. Timothy seed averages about 48 lb. per bushel. The usual amount sown per acre is 12 quarts. At this rate, how many bushels are required for a 20-acre field?
6. At 16 qt. per acre, how many bushels are needed to sow 10 acres?
7. The following mixtures of seeds are sown for hay:
Make and solve 5 problems about these mixtures.
8. Make and solve 5 problems about the following:
1. What is the cost of 10 dictionaries at $9.85 each? How is the result found?
2. When 100 cans of tomatoes cost $8.50, what is the price per can? How is the result found?
3. When 10 pumps cost $28.40, what is the price of each? How is the result found?
4. At the rate of .45 mi. per minute, how far does the train travel in 100 minutes? How is the result found?
5. How is a number expressed decimally multiplied by 10? By 100? How is such a number divided by 10? By 100?
6. How many bushels of apples can a man pick in 10 days at the rate of 36 bu. a day? What part does he pick in 5 days? How many bushels?
7. Following the plan of Exercise 6, find how many bushels of apples a man can pick in 5 days at the rate of 42 bushels a day.
8. 5 is how many halves? To multiply by 5 is to multiply by how many halves? What is the easiest way to multiply by 5?