PRACTICE IN FINDING AVERAGES

1. Helen's mother found that for a family of 5 the cost of food one week was $21. That was an average of how much for each?

2. She found that the food for a whole year cost them $789. That was an average of how much for each of the five? It was an average of how much per week?

3. Helen's father spent $93.80 last year for coal to heat his house for 7 months during the winter months. That is an average of how much per month?

4. Their laundry bills for the year amounted to $98.60. That was an average of how much per month? Of how much per week?

5. Her father pays $510 per year for house rent. How much is that per month?

6. It cost a party of 16 boys $86.90 to go on a camping trip. That was an average of how much per boy?

7. In a small school of 586 pupils it cost $35,480 to run the schools one year. That was an average cost of how much per pupil?

8. A Western farmer had 285 acres of wheat, from which he harvested 8396 bu. Find the average yield per acre to the nearest hundredth.

9. Five boys on a football team averaged 139 lb. each, and 4 others on the same team averaged 148 lb. each. Find to the nearest tenth the average weight of the nine.

10. During the month of June, Mr. Brown used 36 gal. of gasoline and drove 698 mi. In July, he drove 536 mi. and used 29 gal. And in August, he drove 1026 mi. and used 54 gal. Find the 3-month average mileage per gallon of gasoline.

To divide by 25, multiply by four and point off two more decimal

18. When 12 yd. of cloth cost $17.50, what was the price per yard?

19. At 25¢ per yard, how much gingham can be bought for $3.50?

20. When a roast weighing 61 b. cost $3, what was the price per pound?

21. When a bolt of sheeting containing 334 yd. cost $6, what was the cost per yard?

22. A remnant of cloth containing 8 yd. scld for $10. What was the cost per yard?

A NUMBER RACE

Write down the numbers 1, 2, 3, and so on, in columns for the 45 exercises given below. At a signal from your teacher, begin writing the missing number. The first to finish stands and all stop. The teacher then gives the correct answers and each finds how many he had correct. The one having the most wins. What was your rank?

CHAPTER IV

USING AND PICTURING LARGE NUMBERS

In your daily reading, and in your geography, you see large numbers that you must be able to interpret in order to understand what you read. Sometimes numbers are pictured by lines. Such pictures are called graphs.

DIVIDING BY LARGE NUMBERS

1. In a recent year the United States raised 451,185,000 bu. of potatoes. Estimating the population at 106,000,000 that year, find how many bushels that would be for each person.

2. In a recent year we raised 788,000,000 bu. of wheat. With a population of 106,000,000, how many bushels was that for each?

3. The corn crop in a recent year was 3,021,000,000 bu. The number of acres planted was 103,100,000.

average yield per acre.

The fourth order to the left is billions.

Find the

4. One year there were 40,700,000 acres of oats in the United States and 1,302,000,000 bu. were raised. Find the average yield per acre..

MULTIPLYING BY NUMBERS ENDING IN ZEROS

1. Find the product of 34,000 × 57,000.

57,000

34,000

228

171

1,938,000,000

Disregard the zeros in performing the multiplication and bring down in the product as many zeros as there are in both factors.

20. If we each need 80 lb. of sugar per

year, how many

pounds will the 106,000,000 persons in the United States need? How many tons?

21. If we each need 190 lb. of meat per year, how much will we all need?