3. Lesson 1-2 Glencoe Algebra 1
Order of operations
Lesson 1-2 Glencoe Algebra 1

4. Learning Goal
Evaluate numerical expressions and algebraic expressions by using the order of operations.
Then/Now

5. Vocabulary evaluate – to find the value of
order of operations – the rule which lets you know which operation to perform first.
Vocabulary

6. 26 = 2 ● 2 ● 2 ● 2 ● 2 ● 2 Use 2 as a factor 6 times. = 64 Multiply.
Evaluate Expressions
Evaluate 26.
26 = 2 ● 2 ● 2 ● 2 ● 2 ● 2 Use 2 as a factor times.
= 64 Multiply.
Answer: 64
Example 1

7. Evaluate 44.
A. 64
B. 128
C. 192
D. 256
Example 1

8. KC

9. 48 ÷ 23 ● 3 + 5 = 48 ÷ 8 ● 3 + 5 Evaluate powers.
Use Order of Operations
Evaluate 48 ÷ 23 ●
48 ÷ 23 ● = 48 ÷ 8 ● Evaluate powers.
= 6 ● Divide 48 by 8.
= Multiply 6 and 3.
= 23 Add 18 and 5.
Answer: 23
Example 2

10. Evaluate [(92 – 9) ÷ 12]5.
A. 6
B. 15
C. 30
D. 45
Example 2

11. (8 – 3) ● 3(3 + 2) = 5 ● 3(5) Evaluate inside parentheses.
Expressions with Grouping Symbols
A. Evaluate (8 – 3) ● 3(3 + 2).
(8 – 3) ● 3(3 + 2) = 5 ● 3(5) Evaluate inside parentheses.
= 5 ● 15 Multiply 3 by 5.
= 75 Multiply 5 by 15.
Answer: 75
Example 3

12. 4[12 ÷ (6 – 2)]2 = 4(12 ÷ 4)2 Evaluate innermost expression first.
Expressions with Grouping Symbols
B. Evaluate 4[12 ÷ (6 – 2)]2.
4[12 ÷ (6 – 2)]2 = 4(12 ÷ 4)2 Evaluate innermost expression first.
= 4(3)2 Evaluate expression in grouping symbol.
= 4(9) Evaluate power.
= 36 Multiply.
Answer: 36
Example 3

13. Evaluate the power in the numerator.
Expressions with Grouping Symbols C.
Evaluate the power in the numerator.
Multiply 6 and 2 in the numerator.
Subtract 32 and 12 in the numerator.
Example 3

14. Evaluate the power in the denominator.
Expressions with Grouping Symbols
Evaluate the power in the denominator.
Multiply 5 and 3 in the denominator.
Subtract from left to right in the denominator.
Answer: 2
Example 3

15. A. Evaluate the expression 2(4 + 7) ● (9 – 5).
B. 66
C. 88
D. 68
Example 3

16. B. Evaluate the expression 3[5 – 2 ● 2]2.
C. 108
D. 3
Example 3

17. C.
A. 1 B.
C. 4 D.
Example 3

18. Evaluate 2(x2 – y) + z2 if x = 4, y = 3, and z = 2.
Evaluate an Algebraic Expression
Evaluate 2(x2 – y) + z2 if x = 4, y = 3, and z = 2.
2(x2 – y) +z2 = 2(42 – 3) + 22 Replace x with 4, y with 3 and z with 2.
= 2(16 – 3) + 22 Evaluate 42.
= 2(13) + 22 Subtract 3 from 16.
= 2(13) + 4 Evaluate 22.
= Multiply 2 and 13.
= 30 Add.
Answer: 30
Example 4

19. Evaluate x3 – y2 + z, if x = 3, y = 2, and z = 5.
B. 28
C. 36
D. 10
Example 4

20. Write and Evaluate an Expression
ARCHITECTURE Each side of the Great Pyramid at Giza, Egypt, is a triangle. The base of each triangle once measured 230 meters. The height of each triangle once measured 187 meters. The area of a triangle is one-half the product of the base b and its height h.
Example 5

21. Write and Evaluate an Expression
A. Write an expression that represents the area of one side of the Great Pyramid.
Example 5

22. B. Find the area of one side of the Great Pyramid.
Write and Evaluate an Expression
B. Find the area of one side of the Great Pyramid.
Replace b with 230 and h with 187.
Multiply 230 by 187.
Multiply by 43,010.
Answer: The area of one side of the Great Pyramid is 21,505 m2.
Example 5

23. Find the area of a triangle with a base of 123 feet and a height of 62 feet.
A ft2
B ft2
C. 15,252 ft2
D. 32 ft2
Example 5

24. Homework
page 13 #15-35 odd; #36-38; #39-53 odd; #65-68

25. End of the Lesson