1. 1-2B Order of Operations
Algebra Glencoe McGraw-Hill Linda Stamper

2. In arithmetic and algebra, order of operations is used to simplify an expression involving more than one operation.
( )
, [ ]
, { }
First do operations within grouping symbols.
Then evaluate powers.
Then do multiplication and division from left to right.
Finally, do addition and subtraction from left to right.
A fraction bar also acts as a grouping symbol. It indicates that the numerator and denominator should each be treated as a single value.

3. The answer does NOT have absolute value bars!
The absolute value of a number is its distance from zero on a number line. The symbol |a| represents the absolute value of a. Note: Distance cannot be negative.
The answer does NOT have absolute value bars! 7 • •

4. The answer does NOT have absolute value bars!
Evaluate the expression.
The answer does NOT have absolute value bars! 12 • •

5.  Example 1 Evaluate the expression. –|3|   – 3
–|–29|  
– 29

6. If the common sign is positive, the + is not written!
Rules of Addition
To add two numbers with the same sign:
Step 1 ADD
Step 2 ATTACH the common sign
–8 + (–5)
8 + 5
– 13 13
If the common sign is positive, the + is not written!

7. Rules of Addition To add two numbers with the opposite signs:
Step 1 SUBTRACT (to remove zero pairs)
Step 2 ATTACH the sign of the number with the
larger absolute value.
4 + (–7) –3

8. Let yellow = positive Let red = negative
When you add two numbers with opposite signs,
you will need to subtract (take away) the zero pairs.

9. Rules of Subtraction
Adding the opposite of a number is equivalent to subtracting the number.
Subtraction
6 – 4 = 2
Addition
6 + (– 4) = 2      

10. Rules for Multiplication
The product of a positive number and a negative number is negative.
12(–10) = –120
The product of a negative number and a negative number is positive.
–12(–10) = 120
Summary
If the signs are the same, the product is positive.
If the signs are not the same, the product is negative.

11. The Sign of a Quotient Rule
The quotient of a positive number and a negative number is negative. 25 –5 –5
The quotient of a negative number and a negative number is positive.
–25 –5 5
Summary
If the signs are the same the quotient is positive.
If the signs are not the same the quotient is negative.

12. White Board
Practice

13. Evaluate.

14. Evaluate.

15. Evaluate.

16. Evaluate.

17. Evaluate.
When substituting a value into an expression, use parentheses.

18. Evaluate.
When substituting a value into an expression, use parentheses.

19. Evaluate.

20. Evaluate.

21. Homework
1-A4 Handout A4.