Rules for Integers

ADDITION RULES FOR INTEGERS

1. If the signs are the same, you will add the numbers and keep the sign

ex. -19 + (-3) = -22
ex. 4 + 27 = 31

2. If the signs are different you will subtract the numbers and take the sign of the number furthest from zero

ex. -20 + 13 = -7
ex. 16 + (-42) = -26

"Keep the sign of the larger number, and subtract the smaller number from the larger number."

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SUBTRACTION RULES FOR INTEGERS

1. Leave the first integer alone (Leave)

2. Change the subtraction sign to an addition sign (Switch)

3. Change the sign of your second integer (Flip)

4. Follow the addition rules above

ex. -17 - (19) =
-17 + (+9) = -8

ex. 23 - 37 =
23 + (-37) = -14

Remember: Leave, Switch, Flip

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MULTIPLICATION RULES FOR INTEGERS

1. If the signs are the same, multiply the numbers and the answer is positive

ex. (-3)(-4) = 12
ex. (6)(12) = 72

2. If the signs are different, multiply the numbers and the answer is negative

ex. (-7)(8) = -56
ex. (14)(-3) = -42

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DIVISION RULES FOR INTEGERS

1. If the signs are the same, divide the numbers and the answer is positive

ex. -140 ÷ (-20) = 7
ex. 200 ÷ 50 = 4

2. If the signs are different, divide the two numbers and the answer is negative

ex. 56 ÷ (-8) = -7
ex. -24 ÷ 12 = -2

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