1.5 ­ Adding and Subtracting Real Numbers.notebook
September 10, 2015
9/10: "24"
Make "24" using each number exactly once.
You can rearrange them and use any operations.
1.
2, 4, 6, 9
2.
4, 5, 6, 8
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1.5 ­ Adding and Subtracting Real Numbers.notebook
September 10, 2015
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1.5 ­ Adding and Subtracting Real Numbers.notebook
September 10, 2015
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1.5 ­ Adding and Subtracting Real Numbers.notebook
September 10, 2015
1.5: Adding & Subtracting Real Numbers
Date: 9/10
Ex 1). What is each sum?
a) 4 + 7
b) 4 + (­7)
c) ­4 + 7
­10
­9
­8
­7
­6
­5 ­4
­3
­2
­1
0
1
2
3
4
5
6
7
8
9
10
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1.5 ­ Adding and Subtracting Real Numbers.notebook
September 10, 2015
The absolute value of a number is its distance from zero on a number
).
line. Absolute value is always nonnegative (
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1.5 ­ Adding and Subtracting Real Numbers.notebook
September 10, 2015
Adding Real Numbers
Adding Numbers with the Same Sign:
Add their absolute values. The sum has the same sign as the
addends.
ex:
Adding Numbers with Different Signs:
Subtract their absolute values. The sum has the same sign as the
addend with the greater absolute value.
ex:
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1.5 ­ Adding and Subtracting Real Numbers.notebook
September 10, 2015
Ex 2). What is each sum?
a) ­14 + 9
b) ­15 + (­4)
c) ­3.6 + 10.8
d)
e)
f)
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1.5 ­ Adding and Subtracting Real Numbers.notebook
September 10, 2015
Two numbers that are the same distance from zero on a number line
but lie in opposite directions are called opposites.
ex:
A number and its opposite are called additive inverse, because they
will always add to ____.
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1.5 ­ Adding and Subtracting Real Numbers.notebook
September 10, 2015
Inverse Property of Addition
For every real number a, there is an additive inverse ______ such that:
___________________________
ex:
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1.5 ­ Adding and Subtracting Real Numbers.notebook
September 10, 2015
Subtracting Real Numbers
To subtract a real number, add its opposite: ______________________
ex:
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1.5 ­ Adding and Subtracting Real Numbers.notebook
September 10, 2015
Ex 3). What is each difference?
a) ­6 – (­12)
b) 2.1 – 9.6
c) 5 – 5
d)
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1.5 ­ Adding and Subtracting Real Numbers.notebook
September 10, 2015
Ex 4). A reef explorer dives 20 feet to photograph brain coral and then
rises 7 feet to travel 31 feet to survey the base of the reef. Then the diver
dives 18 feet to see an underwater cavern. What is the location of the
cavern in relation to sea level?
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1.5 ­ Adding and Subtracting Real Numbers.notebook
September 10, 2015
Homework:
pg. 33 #1 – 9, 10 – 40 (e), 44, 49 – 51
*NO CALCULATOR*
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1.5 ­ Adding and Subtracting Real Numbers.notebook
September 10, 2015
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