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

2. Warm Up
Perform the operations in order from left to right.
– 2
2. 9  3 + 1
3. 7 – 3 + 5
4. 20 ÷ 4 + 6 10 28 9 11

3. Problem of the Day
= 1
Put the appropriate plus or minus signs between the numbers so that the total equals 1.
0 + 1 – – 89 = 1

4. Learn to use the order of operations.

5. Vocabulary
numerical expressions
evaluate
order of operations

6. 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 –
5,006  19
When you evaluate a numerical expression, you find its value.

7. 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.

8. The first letters of these words can help you remember the order of operations.
Please Parentheses
Excuse Exponents
My Multiply
Dear Divide
Aunt Add
Sally Subtract
Helpful Hint

9. 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

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

11. 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

12. 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

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

14. 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

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

16. 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

17. 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   3 39
Mr. Kellett spent $39 on CDs.

18. 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   4 56
Ms. Nivia spent $56 on CDs.

19. Lesson Quiz
Evaluate each expression.
 2
2. (12 – 5)2 – 10
 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   3. 23 39 16 49
$32