1. Rational Numbers

2. Different Types of Numbers??
Natural – “Counting Numbers” ex. 1, 2, 3, 4, 5…
Whole Numbers – ex. 0, 1, 2, 3, 4, 5… o
Integers – ex. …-5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5…

3. Let’s Think About + and -
Start with 2 and add 3 to make 5 (go to the right)
Subtract 3 to get back to 2 (go to the left) 2 3
Adding and Subtracting “un-do” each other
That means they are Inverses of each other

4. Inverse:“Un-do” What would be the inverse of adding 5? Subtracting 5
What would be the inverse of subtracting 3
Adding 3
What would be the inverse of +8 (positive 8)
-8 (negative 8)
What would be the inverse of (negative 2)
+2 (positive 2)

5. Is zero positive or negative?
Neither!
because positive and negative numbers are
defined by zero.
Positive numbers are larger than zero
Negative numbers are smaller than zero
*Think about it…ZERO can’t be larger or smaller than itself !

6. Subtracting More Than There Is
ex. 3– 5 = ?
3 – 5 = -2
COUNT Left TO Subtract

7. -4 + 3 = -1 Adding to a Negative COUNT RIGHT TO ADD ex. –4 + 3 = ?
= -1
COUNT RIGHT TO ADD

8. Here’s the Trick for ADDITION
SAME signs ADD and KEEP the sign
ex = -6
OPPOSITE signs SUBTRACT and KEEP the sign of the BIGGER number
ex = -1

9. Here’s the Trick for SUBTRACTION
to subtract Add its OPPOSITE
ex = 4 + (- 2) = 2
ex = -5 + (- 7) = -12
ex. -2 – (-3) = = 1

10. Multiplication and Division
Same signs POSITIVE
ex. -5 x -3 = 15
ex. 5 x 6 = 30
Opposite signs Negative
ex. -2 x 3 = -6
ex. 7 x -2 = -14