1. Problem of the Day Evaluate each expression for x = 9. 1. 7 + x 2. 4x
4. 36 16 36 19 4 x

2. In word problems, you may need to identify the action to translate words into math.
Operation
Put together or combine
Add
Find how much more or less
Subtract
Put together groups of equal parts
Multiply
Separate into equal groups
Divide

3. Additional Example 1A: Social Studies Application
Lake Superior is the largest lake in North America. Let a stand for the area in square miles of Lake Superior. Lake Erie has an area of 9,910 square miles. Write an expression to show how much larger Lake Superior is than Lake Erie.
To find how much larger, subtract the area of Lake Erie from the area of Lake Superior.
a – 9,910
Lake Superior is a – 9,910 square miles larger than Lake Erie.

4. Additional Example 1B
Let p represent the number of colored pencils in a box. If there are 26 boxes on the shelf, write an algebraic expression to represent the total number of pencils on the shelf.
To put together 26 equal groups of p, multiply 26 times p.
26p, or 26 • p
There are 26p pencils on the shelf.

5. Check It Out: Example 1A
The salary of the governor of Florida for the 2008–2009 fiscal year is $132,932. This is d dollars more than Leones makes as a landscaper. Write an expression for Leones’ salary.
132,932 - d

6. Check It Out: Example 1B
A group of n friends go to the movies. They purchase adult tickets for $38. Write an expression for the price of one adult ticket.
38 ÷ n or 38 n

7. Check It Out: Example 1C
Beth has a pet cat named Buddy. In 3 years, Buddy will be b years old. Beth got Buddy when he was 2 years old. Write an expression that represents how many years Beth has had Buddy.
b - 5

8. +
Operation
Numerical Expression
Words
Algebraic Expression
There are several different ways to write math expressions with words.
28 added to 37
37 plus 28
the sum of 37 and 28
28 more than 37
x + 28
28 added to x
x plus 28
the sum of x and 28
28 more than x

9.  90 — 12 k — 12 Operation Numerical Expression Words
12 subtracted from 90
90 minus 12
the difference of 90 and 12
12 less than 90
take away 12 from 90
Words
Algebraic Expression
k — 12
Words
12 subtracted from k
k minus 12
the difference of k and 12
take away 12 from k

10.  8  48 or 8  48 or (8)(48) or 8(48) or (8)48 8  w or (8)(w) or 8w
Operation
Numerical Expression
8  48 or 8  48
or (8)(48) or
8(48) or (8)48
8 times 48
48 multiplied by 8
the product of 8 and 48
Words
Algebraic Expression
8  w or (8)(w) or 8w
8 times w
w multiplied by 8
the product of 8 and w
8 groups of w
Words

11.  327  3 or 327 3 n  3 or n 3 Operation Numerical Expression Words
327 divided by 3
the quotient of 327 and 3
Words
n  3 or
Algebraic Expression n 3
Words
n divided by 3
the quotient of n and 3

12. Additional Example 2: Translating Words into Math
Write each phrase as a numerical or algebraic expression.
A. 987 minus 12
987  12
B. x times 45
45 • x or 45x

13. Check It Out: Example 2
Write each phrase as a numerical or algebraic expression.
A. 312 plus 58
B. the quotient of 21 and 10 21 10
21 ÷ 10 or

14. Check It Out: Example 2 continued
Write each phrase as a numerical or algebraic expression.
C. 5 times x
5 x
D. t minus 15
t - 15

15. Additional Example 3: Translating Math into Words
Write two phrases for each expression.
A. 16 __ b
16 divided by b
the quotient of 16 and b
B. (75)(32)
75 times 32
the product of 75 and 32

16. Check It Out: Example 3
A. The Nile River is the world’s longest river. Let n stand for the length in miles of the Nile. The Paraná River is 3,030 miles long. Write an expression to show how much longer the Nile is than the Paraná.
n - 3,030
B. Write the phrase as a numerical or algebraic expression.
42 more than 79

17. Check It Out: Example 3 continued
C. Write two phrases for the expression.
18 - r
r less than 18
the difference of 18 and r

18. Lesson Quizzes
Standard Lesson Quiz
Lesson Quiz for Student Response Systems

19. Lesson Quiz
1. Let x represent the number of minutes Kristen works out in one week. Write an expression for the number of minutes she works out in 4 weeks. 4x
Write each phrase as a numerical or algebraic expression.
2. 7 less than x
3. The product of 12 and w
x  7
12w
Write a phrase for each expression x
5. n  12
x more than 17 or x added to 17
n divided by 12 or the quotient of n and 12

20. Lesson Quiz for Student Response Systems
Tim has 15 more cartoon CDs than Martin has. If n represents the number of CDs Martin has, identify an expression for the number of CDs Tim has.
A. n + 15
B. n – 15
C. 15n
D. n  15

21. Lesson Quiz for Student Response Systems
2. Which of the following represents the given phrase as a numerical or algebraic expression?
35 more than n
A. n + 35
B. n – 35
C. 35n
D. n  35

22. Lesson Quiz for Student Response Systems
3. Which of the following represents the given phrase as a numerical or algebraic expression?
the quotient of w and 26
A. w + 26
B. w – 26
C. 26w
D. w  26

23. Lesson Quiz for Student Response Systems
4. Identify two phrases for the expression
k – 11.
A. 11 added to k or 11 more than k
B. 11 subtracted from k or 11 less than k
C. 11 added to k or 11 less than k
D. 11 subtracted from k or 11 more than k

24. Lesson Quiz for Student Response Systems
5. Identify two phrases for the expression
17w.
A. 17 added to w or 17 more than w
B. 17 times w or 17 more than w
C. 17 times w or the product of 17 and w
D. 17 added to w or the product of w and 17