SIMPLE NUMBERS.

1. Any exact integral divisor of a number (except the number itself and 1) is called a factor of the number. The factors of 6 are The factors of 10 are

and

and

2. A factor that is itself a prime number is called a prime factor. A factor that is itself a composite number is called a composite factor.

2 and 3 are

4 and 6 are

factors of 24.

factors of 24.

3. Every composite number may be resolved into prime

factors.

The prime factors of 12 are 2, 2, and 3.

The prime factors of 18 are 2, 3, and 3.

4. From the above it will be seen that a number is equal to the product of its prime factors. 3 and 7 are the prime factors of; 2, 2, and 7, of

Reduce to equivalent fractions having a common denominator :

3., 4. (Change to)

=

4. Add,, and . (Change to
(j) Find the sum of 863, 953, and 871.

5. From subtract. (Change to) (k) Find the difference of 873 and 2493.

14

=

=

6. Divide by. This means, find how many times }} is contained in 3. I can change fourths and thirds to

-ths.

=

=

13-8
times.

12'

twelfths

twelfths are contained in Story-James can husk a row

of corn in of an hour; in of an hour he can husk

(0) 5 acres)288 acres.

This means, find how many times

5 acres are contained in 288 acres.

(p) 5)625 acres. This means, find 1 fifth of 625 acres. Story.

(a) Multiply $374 by .03. This means, find 3 hundredths

NUMBER STORY.

If one acre of land is worth $374,

1 hundredth of an acre of land is worth

3 hundredths of an acre of land are worth

(b) Multiply $347 by .03.

(d) Multiply $24.6 by .03. (f) At $875 an acre, how land cost?

(c) $537 x .04.

(e) $39.4 x .04.

much will .04 of an acre of

*The pupil should understand that he multiplies $3.74 (not $374) by 3, and should be taught to write the decimal point in the product immediately after writing the tenths' figure of the product.

†This means, find how many times 4 hundredths are contained in 576 hundredths. This means, find 1 fourth of $5.76.

(a) At $5.20 a ton, how much will 4600 lb. of coal cost?

(h) Change 148 yd. to feet.
(j) Change 24 hr. to min.
(1)
Change 35 yr. to mo.
(n) Change 37 lb. to oz.
(p) Change 43 bu. to qts.

3 pk. are

(i) Change 15 yd. to inches.
(k) Change 24 hr. to seconds.
(m) Change 52 wk. to days.
(0) Change 49 gal. to quarts.
(q) Change 56 pk. to pints.

(r) How many square inches in a 5-foot square?

2. Some or all of the faces of a rectangular solid may be squares.

3. If each face of a rectangular solid is a square, the solid is called a

4. If some of the faces of a rectangular solid are oblongs, the solid is not a cube.

is

5. The area of a rectangular surface 3 inches by 4 inches square inches.

6. The solid content of a rectangular solid 3 in. by 4 in. by 2 in. is cubic inches.

is

7. The area of a rectangular surface 3 inches by 5 inches square inches.

8. The solid content of a rectangular solid 3 in. by 5 in. by 2 in. is cubic inches.

is

9. The area of a rectangular surface 2 inches by 5 inches square inches.

10. The solid content of a rectangular solid 2 in. by 5 in. by 3 in. is cubic inches.