FACTORS

268. 1. What two numbers multiplied together give 9 as a product? 3 and 3 are factors of 9. 2. What two numbers multiplied together give 14 as a product? 2 and 7 are factors of 14.

3. What two numbers multiplied together give 21 as a product? 3 and 7 are factors of 21.

4. What two numbers multiplied together give 15 as a product? 3 and 5 are factors of 15.

5. What two numbers multiplied together give 33 as a product? 3 and 11 are factors of 33.

6. What 3 numbers multiplied together give 8 as a product? 2x2x2 are factors of 8.

7. What 3 numbers multiplied together give 12 as a product? 2× 2 × 3 are factors of 12.

8. What 3 numbers multiplied together give 20 as a product? 2x2x 5 are factors of 20.

Oral Exercises

269. Find the missing factors:

Two is one factor of each of the following numbers. What is the other?

270. Give one pair of factors of each of the

10

Review Device-The Wheel

7

6

9

271. Multiply the numbers on the rim by the number in the center. Change the number in the center, using 4, 5, 6, 4 7, 8, and 9.

5

Divide the numbers on the rim by the number in the cen

devices containing these difficult relations should be used.

The various forms in which it is possible to express the relations should be drilled, e.g., 8 x 7 = 56. Variations of this relation are 7 x 8=? How many

8's in 56? How many 7's in 56? 7x?=56.

?×?=56.

Multiplication-Written Exercises

8×?= 56.

1. 2)20 2)40 2)60 2)80 2)90 2)70

2. 3)21 3)30 3)27 3)24 3)36 3)45

6. 7)42 7)35 7)56 7)49 7)63

7)77

8)40 8)56 8)64 8)72

8)48

7. 8)32 8. 9)36 9)54 9)45 9)63 9)81 9)72

9. 10)40 10)50 10)60 10)70 10)80 10)90

Multiplication-Written Exercise

275. 1. Mr. Thomas sells 5 city lots for $625 How much does he receive for the lots?

each.

2. Find the cost of 4 pianos at $375 each.

3. One farmer sells 524 sheep at $4 each. Another farmer receives $5 each for 419 sheep. How much does each farmer receive for his sheep? 4. If 1 doz. eggs cost 48, what is the cost of 10 doz.?

5. A dealer sold 7 automobiles for $750 each. How much did he receive?

276. 1. A picnic party of 8 spent $16 for expenses. What was the share of each?

2. How many pounds of apricots, at 9¢ a lb., can be bought for 99 ?