Pre-Algebra Demystified

PRACTICE

Find the LCD of each of the following fractions:

1.

1

4

and

3

10

2.

7

20

and

13

24

3.

9

10

and

5

18

4.

3

16

,

7

20

, and

5

28

5.

2

5

,

5

18

, and

3

20

ANSWERS

1. 20

2. 120

3. 90

4. 560

5. 180

Addition of Fractions

In order to add two or more fractions, the fractions must have the same

denominator.

To add two or more fractions:

 Step 1 Find the LCD of the fractions.

 Step 2 Change the fractions to equivalent fractions in higher terms with

the LCD.

 Step 3 Add the numerators of the fractions.

 Step 4 Reduce or simplify the answer if possible.

EXAMPLE

Add 101 þ 107.

SOLUTION

Since both fractions have the same denominator, add the numerators and

reduce the fractions:

56 CHAPTER 4 Fractions: Part 2