Integer Rules
Adding Integers
Rule 1: Same signs→add and keep the sign
Examples:
4+5=
(-6) + (-9) =
9 + 10 =
(-8) + (-11) =
Rule 2: Different signs→subtract and keep the sign of the number
with the greatest absolute value
You add the integers and keep the sign of the integer with the greatest
absolute value.
Examples:
(-3) + 6 =
(-5) + 2 =
4 + (-3) =
(-1) + 10 =
Rule 3: Adding integers with different signs and the same absolute
value→the sum is 0
Examples:
7 + (-7) =
(-16) + 16 =
2 + (-2) =
(-12) + 12 =
Subtracting Integers
Rule: Keep-Change-Change (KCC)
1.​ Keep the first number
2.​ Change the subtraction sign to an addition sign
3.​ Change the sign of the second number (positive to negative or
negative to positive)
Examples:
(-9) - (-3) =
(5) - (-9) =
2-5=
(-9) - (-10) =
Multiplying Integers
Rule 1: Same signs→Positive
Examples:
(-7) × (-2) =
(-3) × (-2) =
5×9=
(-4) × (-3) =
Rule 2: Different signs→Negative
Examples:
(-6) × (4) =
(9) × (-3) =
12 × (-3) =
(2) × (-8) =
Dividing Integers
Rule 1: Same signs→Positive
Examples:
12 ÷ 3 =
(-15) ÷ (-3) =
20 ÷ 4 =
(-50) ÷ (-10) =
Rule 2: Different signs→Negative
Examples:
(-24) ÷ 3 =
(-45) ÷ 9 =
60 ÷ (-10) =
72 ÷ (-9) =
×
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