13. There are 640 acres in 1 square mile. How many acres in 150 square miles? In 200? In 420 ?

14. The salary of the president is $50000 a year. How much does he receive in 8 years?

111. 1. The sum of 8+12+16 equals the product of 9 × what number?

2. The sum of 40 14 and 12 + 4 equals 7 × what number?

3. The difference between 35+15 and 24-10 is equal to the product of what two factors? Three factors?

4. The product of what two factors is equal to the sum of 9, 20, and 11?

5. The product of 8 times 9 is equal to 6 times what number?

6. The sum of 25, 13, 8, and 10 is equal to the product of what three factors?

7. What is the sum of 3 times 3 x 4, and 5 times 4 × 3 § What is the difference?

8. What is the product of 15+24-14 by 16-12 ? 9. Which is greater, 9 x 13-6, or 12 times 8-20 ? 10. How much less is 60-5 x 8 than 16+14-10?

48

MULTIPLICATION.

11. Charles is twice as old as George, and George is 12 years old. What is the sum of their ages?

12. What is the cost of 4 brooms at 30 cents each, and 6 pounds of sugar at 11 cents a pound?

13. Mary had 18 cents, and Belle had 3 times as many less 9 cents. How many had both?

14. A young man earned $9 a week, and spent $5 a week for board. How much did he save in 12 weeks?

15. A woman sold a grocer 4 dozen of eggs at 24 cents a dozen, and received in payment half a pound of tea worth 50 cents, and 2 pounds of sugar at 11 cents a pound. How much was still due her?

16. A boy bought a book for 36 cents, a slate for 20 cents, and a pencil for 4 cents. How much change

should he receive from a 1 dollar bill?

17. A lady bought 9 yards of silk at $3 a yard, 3 pairs of kid gloves at $2 a pair, 4 pairs of hose at half a dollar a pair. She gave in payment 4 ten dollar bills. How much change should she receive?

Find the required term in the following equations:

18. 19-728-11=?

19. 8x9-16=7x?

20. 21+6×7=40+?
21. 10 x 12-9x11=?
22. 75-5 x 12-35-?
23. 44+19-(50-23)=?

24. 7x12-25 × 0=? 25. 3x0x5+16=2×? 26. 28+12-6×?=16 27. 9×12+10=120-? 28. 42-20+14=? x9

29. 8+55 (? x8)=7

112. By a little practice, numbers containing three or four figures may be multiplied mentally, by first multiplying the highest order of units, and adding the product of each lower order as found.

1. Multiply 324 by 2.

OPERATION.-2 times 3 hundreds are 600; 2 times 2 tens are 4 tens, or 40, and 600 + 40 are 640; 2 times 4 are 8, and 640 + 8 are 648. Omitting all but results, the required product will be easily and promptly obtained by a strictly mental process. Thus, 600, 640, 648.

In like manner, find the product of

113. 1. If I receive $1500 salary, and pay $370 for board, $281.50 for clothing, $112.75 for books, and $196.65 for other expenses annually, what can I save in 3

years

?

2. A merchant bought 7 hogsheads of sugar at $46.45 a hogshead, and sold it for $53.62 a hogshead. How much did he gain?

3. Paid $2709 for 388 barrels of flour, and sold the same at $9.12 a barrel. How much was the gain ?

4. If a man have an income of $5670 a year and his daily expenses average $7.25, how much can he save in a year of 365 days?

5. What number must be added to 272 × 400 to make the amount 126720 ?

6. What is the difference between 40706 - 308 × 56, and 97 x 340-12400?

7. Multiply 98+6x (37+50) by 64-50 x 5-10.

8. Multiply 675— (77+56) by (3 × 155) — (214—28). 9. A man owing $15760, gave in payment 5 lots of land, worth $730 each, 5 horses, valued at $236.50 each, an interest he had in a coal mine worth $2000, and $1728.75 in money. How much remained unpaid?

MULTIPLICATION.

10. A farm-house is worth $3246, the farm is worth 3 times as much plus $1200, and the stock is worth twice as much as the house, less $1875. What is the value of the whole, and of the farm and stock?

11. What is the difference in the cost of 48 horses at $184.50 each, and of 130 sheep at $4.80 a head?

12. Bought 150 barrels of flour for $1150, and finding 25 barrels of it worthless, sold the remainder at $9 a barrel. Did I gain or lose, and how much? Complete the following equations:

13. (142405) x (1000 850) 5000 = ?

14. (97 × 1000) (75 x 500-420) + 1500 = ? 15. $73.46 ($.94 + $3.02) + $47 × 35 = ?

16. $246.08 × 104 + ($2000 — $240.50) × 10 == ?

115. 1. How many 4's are 12? Are 16? Are 24? 2. How many lots, of 5 acres each, in 20 acres?

3. How many 5's in 15? In 30? In 35? In 50? 4. How many barrels, each holding 3 bushels, will be required for 18 bushels of apples? 21 bushels?

5. How many times can 6 yards of cloth be taken from a piece containing 30 yards.

6. How many times can 6 cents be taken from 23 cents, so as to have 5 cents remaining?

7. Distribute $28 equally among 7 men. dollars will each receive?

How many

Do you find how many times 7 men are contained in $28, or do you find one of 7 equal parts of $28 ?

8. How do you find one of 8 equal parts of a number? Of 9 equal parts? Of 6 equal parts?

Of 48?

9. What is one of 4 equal parts of 40? Of 36? Of 48? 10. What is one of 6 equal parts of 30? Of 42? 11. What is one of 7 equal parts of 56 pounds? 12. How many times 8 cents are 48 cents? Is the result a concrete or an abstract number?

13. What is one of 8 equal parts of 48 cents? Is the result a concrete or an abstract number?