Interesting Integers! Let’s subtract.. What You Will Learn Rules for subtracting Method for...
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Transcript of Interesting Integers! Let’s subtract.. What You Will Learn Rules for subtracting Method for...
Interesting Integers!Let’s subtract.
What You Will Learn Rules for subtracting Method for subtracting
Are you ready??
We will use algebra tiles to solve some subtraction problems
Remember zero pairs – 1 set of opposite colors will be a zero pair
Red is positive
Yellow is negative
1 yellow + 1 red = 0
Let’s try a problem
-2 - 4 =
This is our zero pair bank
Problem: 4 - 2
-2 - 4 =
Remove 4 red (positive)
Problem: 5 - -2
Problem: -3 - -4 =
Subtracting Integers
To subtract integers, add its opposite!2 – 7
2 + (-7)
Follow the add rules
Here are some examples
5 – (+5)
5+ (-5) = 0
5 – (+10)
5 + (-10) = -5
Integer Subtraction RuleSubtracting a negative number is the same as adding a positive. Change the signs and add.
2 – (-7) is the same as
2 + (+7)
2 + 7 = 9!
Here are some more examples.
12 – (-8)
12 + (+8)
12 + 8 = 20
-3 – (-11)
-3 + (+11)
-3 + 11 = 8
2 – (+7)=
4 – (-5) =
-10 – (-6) =
-21 – (+63) =
7-2=5
4 +5 = 9-10 + 6 = -4
63 – 21 = 42
Forget the sign, find the difference, use the sign of the larger
Forget the sign, find the difference, use the sign of the larger
Try these
1. 8 – (-12) =
2. 22 – (-30) =
3. – 17 – (-3) =
4. –52 – 5 =
8 – (-12) = 8 + 12 = 20
2. 22 – (-30) = 22 + 30 = 52
3. – 17 – (-3) = -17 + 3 = -14
4. –52 – 5 = -52 + (-5) = -57
Homework – page 268/269
16 through 28 all
FormativeOrder least to greatest
-10 0 8 -14 22 -1.2 1.3
Solve
-15 + 8 =
-4 - -4 =
5 + -3 =
-4 - +6 =
HomeworkBased on formative results-from textbookOrdering and comparing – pg 24 #1, #2Adding pg 27 #5, #6, #7, #8Subtracting pg 28 #1 #2 #3 #4