Fraction Review

Finding least common denominator

100

What is the least common denominator (LCD) of 1/4 and 1/6?

LCD = 12

200

What is the LCD of 3/8 and 1/12?

 LCD = 24

300

Find the LCD for 2/9 and 5/6

LCD = 18

400

Find the LCD of 7/10 and 3/14

LCD = 70

500

Two fractions have denominators 15 and 18. What is their LCD?

LCD = 90 (15 = 3×5, 18 = 2×3×3 → LCM = 2×3×3×5 = 90)

Adding with common denominators

100

2/7+3/7

5/7

200

5/12 + 4/12

9/12 = 3/4 

300

4/9 + 5/9

8/9

400

12/15 + 1/15

13/15

500

9/20 + 11/20

20/20 = 1

Adding with uncommon denominators

100

1/3 + 1/4

7/12

200

2/5 + 1/6

17/30

300

3/8 + 1/12

11/24

400

5/9 + 2/3

11/9 = 1 2/9

500

7/12 + 5/18

31/36

Subtracting with uncommon denominators

100

3/4 - 1/8

5/8

200

5/6 - 1/4

7/12

300

7/8 - 1/3 

13/24

400

11/12 - 2/5

31/60

500

13/15 - 7/18

43/90

Equivalent fractions

100

Write an equivalent fraction to 1/2 with a denominator greater than 8

5/10

6/12

7/14

etc.

200

Write two fractions equivalent to 3/4

6/8

9/12

12/16

etc.

300

Is 4/6 equivalent to 2/3?

Explain your answer

Yes.

4/6 divided by 2/2 = 2/3

400

Create an equivalent fraction to 5/9 with a denominator of 45

25/45

500

Determine if 7/14, 14/28, and 21/42 are all equivalent to each other. 

Explain why using multiplication or division of numerator and denominator.

Yes — all are equivalent. Each simplifies to 1/2 (divide numerator and denominator by 7, 14, and 21 respectively)