Example 3 Using Mixed Numbers in Real Life

A corn snake that is inches long grows to a length

of inches. How much does it grow?

BIOLOGY

4314

4127

41

2743

14 =–45

2643

14– Rename so its fraction

part is greater than41

27

43

SOLUTION

To find the amount of growth, subtract the original length from the current length.

264

514 +

4

3= + –

Write mixed numbers in expanded form.

Example 3 Using Mixed Numbers in Real Life

Distributive property264

514

4

3= + – –

Commutative property264

3= +

4

514–( )

Subtract integers and fractions.12= +

4

2

Write as a mixed number and simplify.12=

4

212=2

1

ANSWER The snake grows inches.21

12

Example 4 Evaluating Longer Expressions

a. 112–115+119=2 5 9– +

11Write over common denominator.

2 5 9– +

=116 Evaluate numerator from

left to right.

763b.

– + = 3 2 4– +

Commutative property7

32

754 ( ) +

76–73

75

+

=785

Evaluate inside parentheses.

=716 Rename.

Guided Practice

3. GARDENING

for Examples 3 and 4

838A plant that is inches high grows to a height of

inches. Find the amount of growth.875

ANSWER2

12

Evaluate. Then simplify if possible.

4. 43

47

45

++ ANSWER4

33

ANSWER8

315.

815

87

83

+–

Guided Practice for Examples 3 and 4

Evaluate. Then simplify if possible.

6. 31

32

32

+ ANSWER3

15–2 3