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IT COULD BE WORSE
Chapter 2 Integers
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Positive #’s = numbers greater than
zero
Negative #’s = numbers less than
zero
Integers are positive and negative
numbers excluding fractions and
decimals
Zero is an integer, but it’s not + or -
Number Line
Words to live by:
On a number line, you Increasing when you go to the right and
decrease when you go to the left.
If you add, then you go to the right.
If you subtract, then you go to the left.
In an add and subtract Problem when you find 2 signs next to each
other.
Opposite Signs = -Same Signs = +
Note: we won’t add and subtract integers till 2.2
The opposite of a positive number is its negative counterpart
The opposite of a negative number is its positive counterpart
The difference Between Minus and
Negative
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-4 + 5 negative four plus five
7 – (--9) seven minus negative nine
-3 -12 negative three minus twelve
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8 + (-5) Eight plus negative five
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3-2 Three minus 2
-(y) negative why
Calculators have a minus button and a plus/minus
button
Absolute Values
Calculator: abs (x) (Same as anti-lock
braking system)
 Try These:
 Abs(5)
 Abs (-4)
 -abs(-7)
 Write these in order of smallest to
biggest
 Abs(6), abs(-2), -(-1), -4, -abs(-8)
Homework for 2.1
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1 thru 127 EOO
Problems 8, 14, 18, 30, 38, 46, 54,
66, 78, 94, 108, 110, 118, 126
Ouch, my
brain!
2.2 Add & Subtract
Remember the Number Line!
Ex:
4-2
1+3
5-8
2-2
-3+2
-1-2
4+(-5)
(-4)+(-6)+(-8)+9
Notes to remember:
Opposite signs = Same Signs = +
You better try these!
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47+(-53)
-6
Find the sum of -154 and -37
-191
Evaluate –x+y when x=-3 and y =-10
-7
What is 14 less than -8
-22
What is 25 decreased by 68
-43
-4-(-3)+12-(-7)-20
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Apply this!
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Find the temperature after an increase of 10 deg.
Celsius from -3 deg. Celsius.
7 degrees Celsius
The average temperature on the earth’s surface is
57 degrees Fahrenheit. The average temp
throughout Earth’s stratosphere is -70 deg. F. Find
the difference between these temperatures.
127 deg. F
The distance, d, between point a and point b on a
number line is given by the formula d=abs(a-b)
where abs means absolute value of. Find d when a
= -6 and b=5.
d = 11
2.2 Homework
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1 thru 143 EOO
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36, 52, 96, 98, 114, 132, 140, 146