Adding and Subtracting Fractions with Uncommon Denominators

Addition

100

1/1+2/2

4/4

1/1 x 2/2 = 2/2

2/2 x 1/1 = 2/2

2/2 + 2/2 =4/4

200

3/6+6/12

12/12

3/6 X 2/2 = 6/12

6/12 X 1/1 = 6/12

6/12 + 6/12 = 1 or 12/12

300

2/8+1/6

10/24

2/8 x 3/3 = 6/24

1/6 x 4/4 = 4/24

6/24 + 4/24 = 10/24

400

1/2 + 2/4 

1/1

1/2 x 2/2 = 2/4

2/4 x 1/1 = 2/4

2/4 + 2/4 = 4/4

4/4 = 1/1

500

1/3 + 1/6

3/6 

1/3 X 2/2 = 2/6

1/6 X 1/1 = 1/6

2/6 + 1/6 = 3/6

Subtraction

100

8/6 - 1/3

6/6

8/6 x 1/1 = 8/6

1/3 x 2/2 = 2/6

8/6 - 2/6 = 6/6

6/6 = 1/1

200

2/4 - 1/8

3/8

2/4 x 2/2 = 4/8

1/8 x  1/1 = 1/8

4/8 - 1/8 = 3/8

300

1 1/2 - 1 1/3

1/6

1/2 x 3/3 = 3/6 

1/3 x 2/2 = 2/6

1 3/6 - 1 2/6 = 1/6 

400

6/12 - 3/8 

3/12

6/12 x 2/2 = 12/24

3/8 x 3/3 = 9/24

12/24 - 9/24 = 3/12

500

2/5 - 4/10

0/0

2/5 x 2/2 = 4/10

4/10 x 1/1 = 4/10 

4/10 - 4/10 = 0/0

Simplified

100

 simplify 8/7+1/3

 1 10/21

8/7 x 3/3 = 24/21

1/3 x 7/7 = 7/21

24/21 + 7/21 = 31/21

31/21 = 1 10/21

200

simplify 6/7+1/2

 1 5/14

6/7 x 2/2 = 12/14

1/2 x 7/7 = 7/14

12/14 + 7/14 = 19/14 

19/14 = 1 5/14

300

simplify 6/6+1/2

1 3/6

1/2 x 3/3 = 3/6

6/6 x 1/1 = 6/6 

3/6 + 6/6 = 9/6

9/6 = 1 3/6

400

5/6 + 3/2 

2 2/6 

5/6 x 1/1 = 5/6

3/2 x 3/3 = 9/6

5/6 + 9/6 = 14/6

14/6 = 2 2/6

500

7/10 + 4/9

1 13/90

7/10 x 9/9 = 63/90

4/9 x 10/10 = 40/90

63/90 + 40/90 = 103/90

103/90 = 1 13/90

Fractions equivalent to one

100

how do you write 1 whole in fourths 

4/4

1/1 x 4/4 = 4/4

200

how do you write 1 whole in sixths

6/6

1/1 x 6/6 = 6/6

300

how do you write 1 whole in one 

1/1

1/1 x 1/1 = 1/1

400

how do you write 1 whole in three hundredths 

300/300

1/1 x 300/300 = 300/300

500

how do you write 1 whole in five hundred fifty sixths 

556/556

1/1 x 556/556 = 556/556