adding and subtracting fractions

13
Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Chapter 3 Adding and Subtracting Fractions

Upload: francine-richard

Post on 30-Dec-2015

57 views

Category:

Documents


0 download

DESCRIPTION

Chapter 3. Adding and Subtracting Fractions. Adding and Subtracting Like Fractions. 3.1. Adding Like Fractions. Fractions with the same denominator are called like fractions . Fractions that have different denominators are called unlike fractions. Adding Like Fractions. - PowerPoint PPT Presentation

TRANSCRIPT

Copyright © 2011 Pearson Education, Inc.  Publishing as Prentice Hall.

Chapter 3

Adding and Subtracting Fractions

Copyright © 2011 Pearson Education, Inc.  Publishing as Prentice Hall.

3.1

Adding and Subtracting Like Fractions

Martin-Gay, Basic Mathematics, 4e 33

Copyright © 2011 Pearson Education, Inc.  Publishing as Prentice Hall.

Adding Like Fractions

Fractions with the same denominator are called like fractions. Fractions that have different denominators are called unlike fractions.

Like Fractions

2 3 and

5 5

Unlike Fractions

2 3 and

5 4

Martin-Gay, Basic Mathematics, 4e 44

Copyright © 2011 Pearson Education, Inc.  Publishing as Prentice Hall.

Adding Like Fractions

Adding Like Fractions (Fractions with the Same Denominator)

To add like fractions, add the numerators and write the sum over the common denominator.

If a, b, and c represent nonzero whole numbers, we have

a b a b

c c c

5

3

5

2

5

1

+

=

Martin-Gay, Basic Mathematics, 4e 55

Copyright © 2011 Pearson Education, Inc.  Publishing as Prentice Hall.

Examples

Add and simplify.

a.

b.

3 2 3 2

8 8 8

5

8

3 5 4 3 5 4 12 4 11 1

8 8 8 8 8 8 2

Martin-Gay, Basic Mathematics, 4e 66

Copyright © 2011 Pearson Education, Inc.  Publishing as Prentice Hall.

Elayn Martin-Gay, PEARSON PRENTICE HALL, BASIC COLLEGE MATHEMATICS, 3e – Slide #17

Practice Problems

Add and simplify.

1.

2.

3.

P 175

9

7

9

2

9

5

8

1

8

5

8

6

11

7

11

1

11

10

11

71or

11

18

8

15

9

25

11

7110

Adding Like Fractions

4

3

42

32

Martin-Gay, Basic Mathematics, 4e 77

Copyright © 2011 Pearson Education, Inc.  Publishing as Prentice Hall.

Subtracting Like Fractions

Subtracting Like Fractions (Fractions with the Same Denominator)

To subtract like fractions, subtract the numerators and write the difference over the common denominator.

If a, b, and c represent nonzero whole numbers, then

a b a b

c c c

7

4

7

2

7

6

-

=

Martin-Gay, Basic Mathematics, 4e 88

Copyright © 2011 Pearson Education, Inc.  Publishing as Prentice Hall.

Examples

Subtract and simplify.

a.

b.

8 1 8 1

9 9 9

7

9

7 5 2 1

8 8 8

7 5

8 4

Martin-Gay, Basic Mathematics, 4e 99

Copyright © 2011 Pearson Education, Inc.  Publishing as Prentice Hall.

Elayn Martin-Gay, PEARSON PRENTICE HALL, BASIC COLLEGE MATHEMATICS, 3e – Slide #17

Practice Problems

Add and simplify.

4.

5.

P 175

12

5

12

2

12

7

10

1

10

9

10

8

10

19

12

27

5

4

52

42

Subtracting Like Fractions

Martin-Gay, Basic Mathematics, 4e 1010

Copyright © 2011 Pearson Education, Inc.  Publishing as Prentice Hall.

Solving Problems by Adding or Subtracting Like Fractions

Find the perimeter of the following rectangle.

Rectanglemeter 12

5

meter 12

7

Perimeter 12

7

12

7

12

5

12

5

12

7755

12

24 2m 2

Martin-Gay, Basic Mathematics, 4e 1111

Copyright © 2011 Pearson Education, Inc.  Publishing as Prentice Hall.

Elayn Martin-Gay, PEARSON PRENTICE HALL, BASIC COLLEGE MATHEMATICS, 3e – Slide #17

Practice Problems

Add and simplify.

7. If a piano student practices the piano 3/8 of an hour in the morning and 1/8 of an hour in the evening, how long did she practice that day?

8.

P 176-177

8

4

8

1

8

3

4

7

4

13

4

6

4

713

8

13

2

3

22

32

Solving Problems by Adding or Subtracting Like Fractions

hr2

1

24

4

A jogger ran 13/4 miles on Monday and 7/4 miles on Wednesday. How much farther did he run on Monday than on Wednesday?

Martin-Gay, Basic Mathematics, 4e 1212

Copyright © 2011 Pearson Education, Inc.  Publishing as Prentice Hall.

Example

A recipe calls for 1/3 of a cup of brown sugar and 2/3 of a cup of white sugar. How much total sugar is in the recipe?

Total sugar = brown sugar + white sugar

The total amount of sugar needed in the recipe is 1 cup.

1 2

3 33

13

Martin-Gay, Basic Mathematics, 4e 1313

Copyright © 2011 Pearson Education, Inc.  Publishing as Prentice Hall.

DONE