chapter 1: sections 3&4 evaluate integers ab value
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Chapter 1, Section 3: Evaluating Integers, Section 4: Absolute value. Notes from September 2nd, 2009TRANSCRIPT
Chapter 1Section 3: Evaluating ExpressionsSection 4: Integers and Absolute ValueBy Ms. Dewey-Hoffman, 2009 http://msdhpowerpoints.blogspot.com/
Page 2
Evaluating Variable Expressions
Evaluate a Variable Expression
– Replace each variable with a number.
– Use Order of Operations to Simplify.
Example Problems:
– Evaluate 4y – 15, y = 9
1) 4(9) – 15 Replace variable with a number.
2) 4(9) = 36 Order of Operations. Multiplication.
3) 36 – 15 = 21 Simplify. Subtraction.
Page 3
Example Problems: Try These, Show Steps.
6(g + h), for g = 9, h = 7
2xy – z, for x = 4, y = 3, z = 1
r + s, for r = 13, s = 11
2
Page 4
Word Problems
Bottles of energy drinks come 24 bottles to a case.
How many cases does a store need to order if they want 120 energy drink bottles?
An online store that sells only gummies (worms and bears) and charges $0.75 for every pound that is ordered, plus a fee of $6.00 for shipping costs. Write an expression that relates the total price of an order in p pounds.
Page 5
Integers
Integers
– Whole numbers and their opposites. No decimals or fractions.
Opposites
– The distance a number is from zero, but on the opposite side of zero.
– Opposite of 7 is –7, opposite of –9 is 9.
– There is no opposite of zero!
– A negative sign means “opposite”.
Example Problems: Simplify
1) The opposite of –9
2) The opposite of positive 27
3) -(-6)
4) -(-(-7)
Page 6
Absolute Value
Absolute Value
– Is the measured distance a number is from zero.
– The absolute value of 7 is 7.
– The absolute value of –9 is 9.
– DISTANCE IS ALWAYS POSITIVE.
Treat absolute value bars as grouping simples (or parentheses!).
– Simplify inside the bars using Order of Operations.
Page 7
Absolute Value Example Problems
– |-3|
– -|-3|
– 4 - |-2|
– The opposite of the absolute value of negative seven.
– The opposite of the opposite of the absolute value of positive 8.
Page 8
Assignment #2
Pages 15-16: 11-33 odd. Show steps.
Pages 19-20: 12-38 even. Show steps.
Extra Credit: Page 21: 56-59 all. Just answer, do not need to copy problem.
Remember!
Box answers.
Copy problems.
Show steps!
Due September 3rd, 2009.