Adding and Subtracting Fractions with Unlike Denominators Part 2 SOL: 4.9 The student will a) add and subtract with fractions having like and unlike denominators of 12 or less, using concrete materials, pictorial representations, and paper and pencil; b) add and subtract with decimals through thousandths, using concrete materials, pictorial representations, and paper and pencil; and c) solve problems involving addition and subtraction with fractions having like and unlike denominators of 12 or less and with decimals expressed through thousandths, using various computational methods, including calculators, paper and pencil, mental computation, and estimation. Objectives: The student will solve addition and subtraction problems involving fractions with unlike denominators of 12 or less. Materials: Fraction strips worksheet, worksheet, scratch paper, multiplication chart Instructional Activities: 1. Review using fraction strips and multiplication chart to find least common denominator as a whole group. 2. Review converting to an equivalent fraction (based on LCD found). 3. Review using skills from steps 1 and 2 to add and subtract fractions. 4. Students do worksheet using scratch paper to convert fractions; teacher wanders and helps those struggling. 5. Students write answers on the board and go over worksheet as a class. Assessment: Formative—evaluation of student understanding during whole group instruction Summative—worksheet, textbook page 573 #1-25 for homework Differentiation: Low ability students can use fraction bars when working on worksheet, Anna may use calculator. High ability students can simplify their answers.

Name__________________

Date__________________

Adding and Subtracting Fractions Solve each problem. 3

1.

1

+ =

8

2

8

2.

2

− =

9

6

5

3.

1

12 5

4.

8 8

5.

9 3

6.

8.

9.

10.

3

1

+ = 8 2

+ = 6

1

+ =

4

7.

− =

2

2 4 5 6 1 3

1

− = 3 2

+ = 3

−

7 9

3

11.

12.

13.

14.

15.

16.

17.

18.

=

19.

− =

20.

12 2 3

4 8 8 9 1 2 7 8 1 2 1 2 1 5 5 6 1 2 2 4

1

− = 4 4

− = 6 3

+ = 8 3

− = 4 5

+ = 6 3

− = 8

+ −

4 10 7 12

23.

24.

25.

26.

27.

=

28.

2 5

+ = 6

22.

=

+ = 1

21.

29.

30.

8 9 7 8

3

+ = 6 1

− = 4

5

1

10 1 3 2 8 5 6 3 4 5 7 6 8 2 3

− = 5

4

+ = 6 3

+ = 4 4

− = 9

2

+ = 8 1

− = 7 1

+ = 2 2

− = 4

Name__________________

Date__________________

Adding and Subtracting Fractions Solve each problem. 3

1.

1

+ =

8

2

8

2.

2

− =

9

6

5

3.

1

12 5

4.

8 8

5.

9 3

6.

8.

9.

10.

3

1

+ = 8 2

+ = 6

1

+ =

4

7.

− =

2

2 4 5 6 1 3

1

− = 3 2

+ = 3

−

7 9

3

11.

12.

13.

14.

15.

16.

17.

18.

=

19.

− =

20.

12 2 3

4 8 8 9 1 2 7 8 1 2 1 2 1 5 5 6 1 2 2 4

1

− = 4 4

− = 6 3

+ = 8 3

− = 4 5

+ = 6 3

− = 8

+ −

4 10 7 12

23.

24.

25.

26.

27.

=

28.

2 5

+ = 6

22.

=

+ = 1

21.

29.

30.

8 9 7 8

3

+ = 6 1

− = 4

5

1

10 1 3 2 8 5 6 3 4 5 7 6 8 2 3

− = 5

4

+ = 6 3

+ = 4 4

− = 9

2

+ = 8 1

− = 7 1

+ = 2 2

− = 4