Download 2 +

Do Now 9/29/10

Take out HW from last night.


Copy HW in your planner.



Textbook page 32, #24-32 all, #34-40 evens, #4858 evens
Text page 36, #12-30 evens, #36-46 even
Quiz on integer addition and subtraction Friday.
In your journal, define the word SUBTRACT.
Explain how you subtract two numbers.
Homework
Textbook page 32, #24-32 all, #34-40
evens, #48-58 evens









24) -14
25) -52
26) 50
27) -26
28) -15
29) -102
30) 13
31) 5
32) 21

34)
 36)
 38)
 40)
 48)
 50)
 52)
 54)
 56)
 58)
-71
-4
-1
a) 2; b) -3; c) -1; d) Game 1
10
-2
-18
even
odd
7
Objective
 SWBAT
subtract integers
Section 1.6
“Subtracting Integers”
subtracting two integers, ADD
the OPPOSITE of the second
number to the first. Instead of subtracting ADD
 When
the OPPOSITE!!
8–5=
Do the “OPP-OPP”
8“Opposite-Opposite”
+ (-5) = 3
ADD the OPPOSITE
Don’t Subtract…
ADD the OPPOSITE!!!
-8 – 6
Instead of subtracting ADD
the OPPOSITE!!
What is the opposite of 6?
ADD the OPPOSITE “OPP-OPP”
-8 + (-6) = -14
-6
Subtraction
Using a Number Line
-5 -4 -3 -2 -1 0 1 2 3 4 5
-1 – (-5) =
“OPP-OPP”
-1 + (+5) =
+5
When you ADD a
POSITIVE NUMBER
-1 + 5 = 4
Subtraction
Using a Number Line
-5 -4 -3 -2 -1 0 1 2 3 4 5
-7
2–7=
“OPP-OPP”
2 + (-7) =
When you ADD a
NEGATIVE NUMBER
2 + (-7) = -5
Try It Out!!
 1).
-8 – 2
-8 + (-2) = -10
 2).
-2 – 5
-2 + (-5) = -7
 3).
6 – (-5) 6 + (+5) = 11
 4).
|-4| – (-8) 4 + (+8) = 12
17 – 33 “Add the Opposite”
17 + (-33)
|17| = 17
|-33| = 33
33 – 17 = - 16
Because 33 has a greater
absolute value than 17 the
answer is “negative”.
-83 – (-25)
“Add the Opposite”
-83 + (+25)
|-83| = 83
|25| = 25
Because 83 has a greater
absolute value than 25 the
answer is “negative”.
83 – 25
= - 58
53 – 85
53 + (-85)
|53| = 53
“Add the Opposite”
|-85| = 85
85 – 53 = - 32
Because 85 has a greater
absolute value than 53 the
answer is “negative”.
Negative or Positive?

Without solving the problem, decide whether the
sum will be positive, negative, or zero. (HINT:
write the problem as a sum).
Add the Opposite !!!
17 – (-2)
-14 – (-14)
17 + (+2)
-14 + (+14)
zero
positive
-13 – 11
-13 + (-11)
negative
73 – 84
73 + (-84)
negative
Try It Out…
-43 – 95
-43 + (-95) = -138
-43 – (-15)
-43 + 15 = -28
37 – (-46)
37 + 46 = 83
-123 – 162
-123 + (-162) = -285
13 – (-13)
13 + 13 = 26
83 – 57
83 + (-57) = 26
“Integer” Cards






Red cards = Negative
Black cards = Positive
Jack = 11, Queen = 12, King =13, Ace = 14 or 1.
Dealer deals each player 2 cards.
The player with the highest difference, gets all
the cards from that round.
The player with the most cards at the end of the
deck wins!
Homework
 Text
page 36, #12-30 evens, #36-46 even