Chapter 7: Fractions

Adding Fractions

100

2/7 +4/7

6/7

200

5/12+6/12

11/12

300

4/18+4/18+9+18

17/18

400

15/50+24/50+7/50

46/50

500

15/75+32/75+24/75

71/75

Subtracting Fractions

100

7/9-4/9

3/9

200

12/14-5/14

7/14 or 1/2

300

18/20-4/20-5/20

9/20

400

27/30-12/30-5/30

10/30 or 1/3

500

46/60-22/60-9/60

15/60

How many ways to make a fraction

100

How many ways can you make 4/9 using addition?

1/9+3/9

2/9+2/9

2 ways

200

How many ways can you make 7/12 using addition?

1/12+6/12

2/12+5/12

4/12+3/12

3 ways

300

How many ways can you make 9/16 using addition?

1/16 + 8/16

7/16 + 2/16

3/16 + 6/16

5/16 + 4/16

4 ways

400

How many ways can you make 12/20 using addition?

1/20 + 11/20

2/20 + 10/20

3/20+ 9/20

4/20 + 8/20

5/20 + 7/20

6/20 + 6/20

6 ways

500

How many ways can you make 13/30 using addition?

1/30 + 12/30

2/30 + 11/30

3/30 + 10/30

4/30 + 9/30

5/30 + 8/30

6/30 + 7/30

6 ways

Adding Mixed numbers

100

1 2/5 + 2 1/5

3 3/5

200

3 4/10 + 2 3/10

5 7/10

300

2 3/15 + 4 6/15

6 9/15

400

1 2/7 + 1 6/7

3 1/7

Parts make an improper fraction (8/7) so add 1 whole to mixed number

500

5 3/8 + 2 5/8

8

Whole numbers = 7

numerators = 8 or 1 whole. 

Add numerator to whole number =8

Subtract mixed numbers

100

3 7/10 - 2 4/10

1 3/10

200

7 7/12- 4 2/12

3 5/12

300

4 8/20- 2 5/20

2 3/20

400

7 5/7 - 2 6/7

4 6/7

500

5 3/10- 1 8/10

3 5/10

Need to borrow from the 5. So 3/10 becomes 13/10 - 8/10. 

Whole number 4 becomes a 4