Fractions

+ or - Like Fractions

100

Adding like fractions:

1/2 + 1/2

2/2 (or 1)

200

Subtract like fractions:

5/9 - 1/9 =

4/9

300

Add like fractions 

4/10 + 5/10 =

9/10

400

Subtract like fractions

17/18 - 12/18 =

5/18

500

Adding like fractions

8/27 + 11/27 =

19/27

Equivalent Fractions

100

1/2 = ?/4

2/4

200

3/5 = ?/10

6/10

300

1/4 = 10/?

10/40

400

2/6 = ?/18

6/18

500

4/7 = 16/?

16/28

+ or - Unlike fractions

100

1/2 + 2/6 = 

5/6 or 10/12

200

5/12 - 1/4 = 

2/12 or 8/48

300

1/4 + 2/7 =

15/28

400

3/5 + 2/9 = 

37/45

500

19/24 - 2/3 = 

3/24 or 1/8

Least Common Multiple

100

Find LCM of 2 & 9

2: 2,4,6,8,12,14,16,18

9: 9,18

18 is LCM

200

Find LCM of 3 & 7

3: 3,6,9,12,15,18,21

7: 7,14,21

21 is LCM

300

Find LCM of 9 & 12

9: 9, 18, 27, 36

12: 12, 24, 36

36 is LCM

400

Find LCM of 7 & 9

7: 7, 14, 21, 28, 35, 42, 49, 56, 63

9: 9, 18, 27, 36, 45, 54, 63

63 is LCM

500

Find LCM of 5 & 12

5: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60

12: 12, 24, 36, 48, 60

60 is LCM 

Miscellaneous

100

What does equivalent mean?

Equal or same value

200

What is a common denominator?

2 fractions having the same bottom number

300

Find the Mistake

1/4 + 2/20 = 1/20 + 2/20

                 = 3/20

What's the first mistake made?

20 is common denominator. Have to create an equivalent fraction for 1/4. 1/4 = 5/20

5/20 + 2/20 = 7/20

Student did not change numerator (did't multiply by a whole).

400

How do you simplify a fraction?

Divide numerator and denominator by Greatest Common Factor. 

500

Simplify 8/24

List the Factors...

8: 1, 2, 4, 8

24: 1, 2, 3, 4, 6, 8, 12, 24

GCF = 8

Divide numerator and denominator by 8. 

Answer is 1/3