Warm Up Evaluate each expression for x = 9. 1. 7 + x 2. 4x 3. 2x + 1 4. 36 16 36 19 4 x

Problem of the Day Draw a square around the numbers of four adjacent days on the calendar for this month. Add all the numbers in the square and subtract four times the first number. What number do you get? 16

Learn to translate between words and math.

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

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.

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.

Check It Out: Example 1A 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. To find how much longer, subtract the length of the Paraná from the length of the Nile. n – 3,030 The Nile River is n – 3,030 miles longer than the Paraná River.

Check It Out: Example 1B Let p represent the number of paper clips in a box. If there are 125 boxes in a case, write an algebraic expression to represent the total number of paper clips in a case. To put together 125 equal groups of p, multiply 125 times p. 125p or 125 • p There are 125p paper clips in a case.

+ Operation Numerical Expression Words Algebraic Expression 37 + 28 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

 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

 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

 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

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

Check It Out: Example 2 Write each phrase as a numerical or algebraic expression. A. 42 less than 79 79  42 B. y divided by 22 y  22 or y 22

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

Check It Out: Example 3 Write two phrases for each expression. A. 17 – 14 14 subtracted from 17 17 minus 14 B. 12 c 12 divided by c the quotient of 12 and c

Lesson Quizzes Standard Lesson Quiz Lesson Quiz for Student Response Systems

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. 4. 17 + x 5. n  12 x more than 17 or x added to 17 n divided by 12 or the quotient of n and 12

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

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

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

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

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