7th grade intigers

7th grade intigers

notes and practice

adding and subtracting integers

RULE 1 - when adding integers with different sides . whichever number is bigger keeps the sign. ex. -12 + 3 = -15 our anwser is negative because the larger number is negative.

RULE 2 - same sign = add or subtract like normal and use the sign of both numbers . ex. -12+ -3 = -15

multiplying and dividing integers

RULE 1 - same signs (positive) different signs (negative) ex. 8 x 2 = 16 OR -8 x -2= 16

RULE 2- double negatives means you get a positive answer . ex. -5 x -7 = 35

adding & subtracting integers practice

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Multiple Choice

-38 + -16

• 54

• 22

• -22

• -54

Multiple Choice

-18 + -9

• -27

• 27

• 9

• -9

Multiple Choice

-3 + -8

• 5

• -5

• -11

• 11

key words for multiplying integers

• of

• twice

• double

• triple

• each *

• every *

• per *

key words for dividing integers

• average

• rate

• split

• share

• per

• half

• equal groups

methods for multiplying and subtracting integers

go to the next slide .

the triangle (my favorite)

when you use the triangle method , you cross out what symbols are already there , your answer is the symbol that's left.

ex. -12 x 3. cross out one of your negitve sign and cross out your positive sign. you only have one sign left. your answer is -36

even & odd

RULE - if there's an odd number of negatives = the answer is negative

if theres and even number of negatives = the answer is positive .

ex. -2 + -2 + 3 + -7 . there are 3 negative numbers , 3 is an old number so our answer is negative.

practice on multiplying and dividing integers

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Multiple Choice

-100 / -5

• 20
• -20

Multiple Choice

3 x (-7)

• 21
• -21

Multiple Choice

48 / (-8)

• 6
• -6

Multiple Choice

-4 x -9

• 36
• -36
• 32
• -32

Multiple Choice

(-5) x (-5)

• 25
• -25