Integer Rules

Integer Rules

Integers

• Positive and negative whole numbers (no fractions)

Adding Integers

• Same signs, add and keep the sign

• Positive + Positive = Positive

• 4 + 5 = 9

• Negative + Negative = Negative

• (-4) + (-5) = -9

Adding Integers (cont.)

• Opposite signs - Subtract the numbers and keep the sign of the bigger number

• (-4) + 5 = 1

• 4 + (-5) = -1

Subtracting Integers

• Change the signs ("add the opposite")

• Keep the sign of the first number

• Change the subtraction to addition

• Change the sign of the second number to the opposite sign.

• If it is positive- change to negative.

• If it is negative- change to positive. 

Subtracting Integers (cont.)

• (4) - (-4) = 4 + 4 = 8

• (-5) - (-5) = -5 + 5 = 0

• 4 - (-5) = 4 + 5 = 9

Multiplying Integers

• SAME SIGNS- POSITIVE. Multiply the numbers. Answer will be positive. 

• (-5) × (-5) = +25

• DIFFERENT SIGNS- NEGATIVE. Multiply the numbers. Answer will be negative

• (+5) × (-5) = -25

Dividing Integers

• SAME SIGNS- POSITIVE. Divide the numbers. Answer will be positive. 

• (-5) ÷ (-5) = +1 

• DIFFERENT SIGNS- NEGATIVE. Divide the numbers. Answer will be negative 

• (+5) ÷ (-5) = -1