Do Now 9/29/10Do Now 9/29/10
Take out HW from last night.Take out HW from last night. Textbook page 32, #24-32 all, #34-40 evens, #48-Textbook page 32, #24-32 all, #34-40 evens, #48-
58 evens58 evens
Copy HW in your planner.Copy HW in your planner. Text page 36, #12-30 evens, #36-46 evenText page 36, #12-30 evens, #36-46 even Quiz on integer addition and subtraction Friday.Quiz on integer addition and subtraction Friday.
In your journal, define the word SUBTRACT. In your journal, define the word SUBTRACT. Explain how you subtract two numbers.Explain how you subtract two numbers.
HomeworkHomework Textbook page 32, #24-32 all, #34-40 Textbook page 32, #24-32 all, #34-40
evens, #48-58 evensevens, #48-58 evens
24) -1424) -14 25) -5225) -52 26) 5026) 50 27) -2627) -26 28) -1528) -15 29) -10229) -102 30) 1330) 13 31) 531) 5 32) 2132) 21
34) -7134) -71 36) -436) -4 38) -138) -1 40) a) 2; b) -3; c) -1; d) Game 140) a) 2; b) -3; c) -1; d) Game 1 48) 1048) 10 50) -250) -2 52) -1852) -18 54) even54) even 56) odd56) odd 58) 758) 7
Section 1.6 Section 1.6 “Subtracting Integers” “Subtracting Integers”
When subtracting two integers, When subtracting two integers, ADD ADD the OPPOSITEthe OPPOSITE of the second of the second number to the first. number to the first.
8 – 5 = 8 – 5 =
Instead of subtracting ADD Instead of subtracting ADD the OPPOSITE!! the OPPOSITE!!
8 8 + (-5)+ (-5) = =ADD the OPPOSITE ADD the OPPOSITE
33Do the “OPP-OPP”Do the “OPP-OPP”““Opposite-Opposite”Opposite-Opposite”
Don’t Subtract…Don’t Subtract…ADD the OPPOSITE!!!ADD the OPPOSITE!!!
-8 – 6 -8 – 6 Instead of subtracting ADD Instead of subtracting ADD the OPPOSITE!!the OPPOSITE!!
What is the opposite of 6? What is the opposite of 6? - 6 - 6
-8 -8 + (-6)+ (-6) = =ADD the OPPOSITEADD the OPPOSITE “OPP-OPP”“OPP-OPP”
-14-14
SubtractionSubtractionUsing a Number LineUsing a Number Line
00 11 22 33 44 55-1-1-2-2-3-3-4-4-5-5
When you ADD a POSITIVE NUMBER
-1 – (-5) = -1 – (-5) = +5
-1 + 5 = 4 -1 + 5 = 4 -1 -1 + (+5)+ (+5) = =
“OPP-OPP”
SubtractionSubtractionUsing a Number LineUsing a Number Line
00 11 22 33 44 55-1-1-2-2-3-3-4-4-5-5
When you ADD a NEGATIVE NUMBER2 – 7 = 2 – 7 =
-7
2 + (-7) = -5 2 + (-7) = -5 2 2 + (-7)+ (-7) = = “OPP-OPP”
Try It Out!!Try It Out!!
1). -8 – 21). -8 – 2
2). 2). -2 – 5-2 – 5
3). 3). 6 – (-5)6 – (-5)
4). 4). ||-4| – (-8) -4| – (-8)
-8 + (-2) = -10-8 + (-2) = -10
6 + (+5) = 116 + (+5) = 11
-2 + (-5) = -7-2 + (-5) = -7
4 + (+8) = 124 + (+8) = 12
17 – 3317 – 3317 + (-33)17 + (-33)
|17| = 17|17| = 17 |-33| = 33|-33| = 33
33 – 17 33 – 17 = 16 = 16 - - Because 33 has a greaterBecause 33 has a greaterabsolute value than 17 the absolute value than 17 the answer is “negative”.answer is “negative”.
““Add the Opposite”Add the Opposite”
|-83| = 83|-83| = 83-83 + (+25)-83 + (+25)
|25| = 25|25| = 25
83 – 25 83 – 25 = 58= 58--Because 83 has a greaterBecause 83 has a greaterabsolute value than 25 the absolute value than 25 the answer is “negative”.answer is “negative”.
|53| = 53|53| = 53
53 + (-85)53 + (-85)
|-85| = 85|-85| = 85
85 – 53 85 – 53 = 32= 32Because 85 has a greaterBecause 85 has a greaterabsolute value than 53 the absolute value than 53 the answer is “negative”.answer is “negative”.
-83 – (-25)-83 – (-25) ““Add the Opposite”Add the Opposite”
53 – 8553 – 85 ““Add the Opposite”Add the Opposite”
--
Negative or Positive?Negative or Positive? Without solving the problem, decide whether the Without solving the problem, decide whether the
sum will be positive, negative, or zero. (HINT: sum will be positive, negative, or zero. (HINT: write the problem as a sum).write the problem as a sum).
17 – (-2)17 – (-2)
positivepositive
-13 – 11-13 – 11
negativnegativee
-14 – (-14)-14 – (-14)
zerozero
73 – 84 73 – 84 negativenegative
17 + (+2)17 + (+2)
-13 + (-11)-13 + (-11)
-14 + (+14)-14 + (+14)
73 + (-84) 73 + (-84)
Add the Opposite !!!Add the Opposite !!!
Try It Out…Try It Out…
-43 – 95-43 – 95= -138= -138
-43 – (-15)-43 – (-15) = -28= -28
37 – (-46)37 – (-46)= 83= 83
-123 – 162-123 – 162= -= -285285
13 – (-13)13 – (-13)= 26= 26
83 – 5783 – 57= 26= 26
-43 + (-95)-43 + (-95) -43 + 15-43 + 15
37 + 4637 + 46 -123 + (-162)-123 + (-162)
13 + 1313 + 13 83 + (-57)83 + (-57)
““Integer” CardsInteger” Cards““Integer” CardsInteger” Cards RedRed cards = Negative cards = Negative BlackBlack cards = Positivecards = Positive Jack = 11, Queen = 12, King =13, Ace = 14 or 1.Jack = 11, Queen = 12, King =13, Ace = 14 or 1. Dealer deals each player 2 cards.Dealer deals each player 2 cards. The player with the The player with the higheshighest difference, gets all t difference, gets all
the cards from that round. the cards from that round. The player with the most cards at the end of the The player with the most cards at the end of the
deck wins!deck wins!