Post on 18-May-2015
transcript
What did Usher do wrong?
Find absolute value
6 – (-9)
6 + (-9)-9 is the largest so
–+ plus – means
subtract-3
Human Number Line
Adding look right
Subtracting look left
Positive walk forward
Negative walk backward
5 + 2
-2 + 4
6-9
-3 – (-9)
5 + (-4)
Subtracting Integers…..What are we really
doing?
??!?!?
Organizing our Thoughts
Integer FoldablePart 2
SubtractingRules
1.Change problem to addition by “adding the opposite”
(+) - (+) = (+) + (-)
(-) - (-) = (-) + (+)
(+) - (-) = (+) + (+)
(-) - (+) = (-) + (-)
1. - 3 – (-5)
2. 4 – 7
3. 6 – (-9)
4. -3 - 8
First ½ Sing to the tune of
"Row Row Row Your Boat"
Same sign add and keepDifferent sign subtract
Take the sign of the farther numberThen it'll be exact!
Is it an addition problem?
Yes
Look at the farthest number
No
Add the opposite
Is the positive or negative number
larger?
Look at the fartheset number
+ is largerFinal answer is
positive
- is larger
Final answer is negative
- Is the largest
+ Is the largest
Organizing our Thoughts
Integer FoldableParts 3 and 4
Multiplying
Rules1. + times - = -2. - times + = -
3.+ times + = + 4.- times - = +
1. -9(-10)2. 4 x -45
3. 4 (30)
4. (-9)•7
Dividing
Rules1. + times - = -2. - times + = -
3.+ times + = + 4.- times - = +
1. -25 ÷ 5
2. -30 /-6
3. 24/12
4. 81 ÷ -9
Worktime Worksheet