1. Unit 1 Rational Numbers
Integers

2. Adding Integers
The sum of two positive integers is always positive. 5+4=9.
The sum of two negative integers is always negative. -5 +(-3)= -8.
The sum of a positive integer and a negative integer is sometimes positive, sometimes negative and sometimes zero.
5 + (-1)= = =0

3. Positive+ Negative
4+ (-2)=
7+ (-8)=
5 + (-5)=
9+ (-13)=

4. Negative + Positive
(-9) + 5=
(-4) + 7=
(-6) + 5=
(-3) + 10=

5. Negative + Negative (-4) + (-4)= (-7) + (-2)= (-1) + (-6)=
(-8) + (-5)=

6. Subtracting Integers To subtract an integer, add its opposite.
4-9=4 + (-9)=-5
Or Keep, Change, Change
-5 – (+7)
Keep the 5, change the – to + and the + to (-7)=-12
11- (-3)= =14

7. Positive – Positive
4 – 8=
5 – 6=
7 – 9=
3 – 12=

8. Positive - Negative
4 – (-5)=
8 – (-1)=
12 – (-7)
3- (-9)

9. Negative - Positive
(-9) - 5=
(-4) - 7=
(-6) - 5=
(-3) - 10=

10. Negative - Negative (-2) - (-4)= (-7) - (-5)= (-5) - (-6)=
(-8) - (-10)=

11. Multiplying Integers
The product of two integers with the same sign is positive.
5X5=25 -5X-5=25
The product of two integers with different signs is negative.
-5X4=-20 5X-4=-20

12. Dividing Integers
The quotient of two integers with the same sign is positive.
25÷5= ÷-5=5
The quotient of two integers with different signs is negative.
-25÷5= ÷5=-4

13. Summary Multiplying and Dividing Integers-
If the signs are the same, the answer is positive.
If the signs are different, the answer is negative.