MULTIPLICATION.

INDUCTIVE

EXERCISES.

29. 1. If 5 boys can sit upon one bench, how many boys can sit upon 3 benches? 5 and 5 and 5 are how many ?

2. If a man earn $3 a day, how many dollars will he earn in 5 days? $3+$3+$3+$3+$3 are how many? Five 3's, or 5 times 3, are how many?

3. What is the sum of $3 taken five times?

4. Count to 15 by 3's. By 5's. How many 3's in 15? How many 5's?

5. There are 7 da. in 1 wk. How many days are there in 4 wk.? 7 da. +7 da. + 7 da. + 7 da. = = ? Four 7's, or 7x4 = ?

6. Should we repeat 7 da. four times, or 4, seven times? Why?

7. Count by 4's to 28. By 7's. How many 4's in 28? How many 7's?

8. Is the result of 4 times 7 and of 7 times 4 the same? 9. At $4 a barrel, what is the cost of 6 barrels of apples? SOLUTION. Six barrels cost 6 times $4, or $24.

10. If $4 is written 6 times in a column and added, what i the sum? If 6 is written 4 times and added, what is the sum?

11, If $4 is multiplied by 6, what is the product?

12. If 8 bu. is written 5 times in a column and added, what is the sum? If 8 bu. is multiplied by 5, what is the product? 13. What will the unit of the number produced by addition or multiplication always be like?

Ans. Like the unit of the number repeated.

12 24 36 48 60 72 84 96 108 120 132 144

ORAL

AND SLATE

EXERCISES.

30. 1. If 1 hat cost $7, what is the cost of 5 hats?

WRITTEN SOLUTION. $7×5

ORAL SOLUTION.

=

cost of the hats.

Five hats cost 5 times $7, or $35.

2. At 6 cents each, what will 5 pencils cost?

3. At 8 cents a pound, what will 6 pounds of soap cost? 9

pounds? 10 pounds? 12 pounds?

4. What is the cost of 5 books, at $4 each?

At $5?

5. Repeat the table from 0 times 2 to 12 times 2.

6. Repeat back from 12 times 2 to 0 times 2. Thus, 12 times 2 are 24, 11 times 2 are 22, 10 times 2 are 20, etc.

7. James gave 5 cents each for 6 oranges. change should he receive from 50 cents?

How much

Recite the following, rapidly from the open book, thus: 9 cords of wood at $4 a cord will cost $36; 6 pairs of boots at $8, will cost $48; at $9, will cost $54, etc.

8. At $4 a cord, what will 9 cords of wood cost?

9 What cost 6 pairs of boots, at $8 a pair? At $9? 10. At 8 cents each, what cost 9 books? 10 books? 11. What cost 9 barrels of flour, at $9 a barrel? At $10? 12. If a man earn $12 in 1 wk., what will he earn in 8 wk.? 13. At $9 a pair, what is the cost of 7 pair of boots? 14. What is the cost of 8 pencils at 6 cts. each? At 7 cts.? 15. At 11 cents a pound, what is the cost of 11 lbs. of sugar? 16. At 12 cents a yard, what cost 9 yards of calico? 17. What cost 10 pounds of ginger, at 11 cents a pound? 18. At $11 a hundred, what will 11 hundred posts cost? 19. What is the cost of 6 tons of coal at $7 a ton? At $8? 20. How many are 8 times $4, minus $7?

21. How many are 7 times 9 pounds, plus 10 pounds? 22. How many are 6 times 12 rods, less 20 rods?

23. How many units are 4 times 9 units? How many tens? Ans. 3 tens and 6 units.

24. How many are 5 times 12 units? How many tens? 25. How many tens are 6 times 5 tens? How many hundreds? How many units?

26. How many are 4 times 6 tens? How many hundreds and tens? How many units?

What is the cost of

27. 9 coats, at $9 each? 28. 11 hats, at $5 each ? 29.

robes, at $12 each? 30. 9 tops, at 8 cents each?

31. 12 tables, at $8 each? 32. 10 desks, at $11 each? 33. 9 maps, at $12 each? 34. 12 globes, at $12 each?

35. At 12 cents a pound, what cost 6 pounds of butter? 36. At $9 a head, what is the cost of 11 head of sheep?

The pupil should raake oral problems for the above. Thus, for "3 × 7." 'What will 7 lemons cost, at 3 cents each?" Another pupil may solve the same by a simple analysis; thus, 7 lemons will cost 7 times 3 cents, or 21 cents.

46. Also, at sight, supply the missing number:

47. Read, and write the result in place of (?):

WRITTEN EXERCISES.

31. 1. How many are 4 times 73?

To obtain the result by addition.

First find the sum of four 3's, or 4 times 3 units, which is 12 units, equal to 1 ten and 2 units. Write the 2 units in the units' place, and reserve the 1 ten to be added to the sum of the tens.

Next, the sum of four 7's, or 4 times 7 tens, is 28 tens, plus 1 ten reserved are 29 tens, or 2 hundreds and 9 tens, which write in the hundreds' and tens' place. Hence, the sum is 292.

In this operation, the multiplicand 73 is written but once; and as it is to be taken 4 times, write the multiplier 4 under it, and commence at the right to multiply. 4 times 3 units are 12 units, or 1 ten and 2 units. Write the 2 units in units' place and reserve the 1 ten to add to the product of the tens.

BY ADDITION

73

73

73 73

Sum, 292

BY MULTIPLICATION.

Multiplicand,

Multiplier,

Product,

73

4

292

Next, 4 times 7 tens are 28 tens, plus 1 ten reserved are 29 tens, or 2 hundreds and 9 tens, which write in the hundreds' and tens' places. Hence, the product is 292, equal to the sum.

Solve by both methods,

2. 3 times 84.

3. 4 times 135.

4. 5 times 234.

6. 4 times $204.

5. 6 times 352.

7. 5 times $425.

8. Multiply 4621 by 4; by 5; by 6; by 7. 9. Multiply 3062 by 6; by 7; by 8; by 9. What is the product

10. Of $5642 by 6? by 5? by 7? by 9?

11. Of 20372 feet by 7? by 9? by 5? by 6?

12. Of 428175 bushels by 4; by 6; by 5; by 7; by 8. 13. Of 932674 cents by 6; by 7; by 4; by 8; by 5. 14. If there are 52 weeks in 1 year, how many there in 8 years?

weeks are