1-4 Order of Operations Warm Up Problem of the Day Lesson Presentation Course 1 Warm Up Problem of the Day Lesson Presentation

Learn to use the order of operations.

Vocabulary numerical expressions evaluate order of operations

When you evaluate a numerical expression, you find its value. A numerical expression is a mathematical phrase that includes only numbers and operation symbols. Numerical Expressions 4 + 8 ÷ 2  6 371 – 203 + 2 5,006  19 When you evaluate a numerical expression, you find its value.

When an expression has more than one operation, you must know which operation to do first. To make sure that everyone gets the same answer, we use the order of operations. ORDER OF OPERATIONS 1. Perform operations in parentheses. 2. Find the values of numbers with exponents. 3. Multiply or divide from left to right as ordered in the problem. 4. Add or subtract from left to right as ordered in the problem.

Additional Example 1A: Using the Order of Operations Evaluate the expression. 15 – 10 ÷ 2 There are no parentheses or exponents. 15 – 10 ÷ 2 Divide. 15 – 5 Subtract. 10

Additional Example 1B: Using the Order of Operations Evaluate the expression. 9 + (21 ÷ 7)  5 9 + (21 ÷ 7)  5 Perform operations within parentheses. 9 + 3  5 Multiply. 9 + 15 Add. 24

Check It Out: Example 1A Evaluate the expression. 12 – 6 ÷ 2 There are no parentheses or exponents. 12 – 6 ÷ 2 Divide. 12 – 3 Subtract. 9

Check It Out: Example 1B Evaluate the expression. 7 + (24 ÷ 6)  3 7 + (24 ÷ 6)  3 Perform operations within parentheses. 7 + 4  3 Multiply. 7 + 12 Add. 19

Additional Example 2A: Using the Order of Operations with Exponents Evaluate the expression. 24 + 6  4 2 + 6  4 4 There are no parentheses. Find the value of the number with the exponent. 16 + 6  4 Multiply. 16 + 24 Add. 40

Additional Example 2B: Using the Order of Operations with Exponents Evaluate the expression. 24 ÷ (9 – 6)  32 – 10 24 ÷ (9 – 6)  32 – 10 Perform operations within parentheses. 24 ÷ 3  32 – 10 Find the value of the number with the exponent. 24 ÷ 3  9 – 10 8  9 – 10 Divide. Multiply. 72 – 10 Subtract. 62

Check It Out: Example 2A Evaluate the expression. 42 + 3  7 42 + 3  7 There are no parentheses. Find the value of the number with the exponent. 16 + 3  7 Multiply. 16 + 21 Add. 37

Check It Out: Example 2B Evaluate the expression. 32 ÷ (8 – 4)  22 – 12 32 ÷ (8 – 4)  22 – 12 Perform operations within parentheses. 32 ÷ 4  22 – 12 Find the value of the number with the exponent. 32 ÷ 4  4 – 12 8  4 – 12 Divide. Multiply. 32 – 12 Subtract. 20

Additional Example 3: Consumer Application Mr. Kellett bought 6 used CDs for $4 each and 5 used CDs for $3 each. Evaluate the following expression to find the amount Mr. Kellett spent on CDs. 6  4 + 5  3 24 + 15 39 Mr. Kellett spent $39 on CDs.

Check It Out: Example 3 Ms. Nivia bought 4 new CDs for $8 each and 6 used CDs for $4 each. Evaluate the following expression to find the amount Ms. Nivia spent on CDs. 4  8 + 6  4 32 + 24 56 Ms. Nivia spent $56 on CDs.

Lesson Quiz Evaluate each expression. 1. 15 + 4  2 2. (12 – 5)2 – 10 3. 3 + 9  2 – 5 4. 43 – 30 ÷ 2 5. Chaz bought 4 football cards for $2 each and 8 baseball cards for $3 each. Evaluate the expression to find the amount Chaz spent on cards: 4  2 + 8  3. 23 39 16 49 $32