Important Facts About Variables: 

1. Variable names are case sensitive. X is not the same as x.

2. There are shortcuts for operations with variables. 
      += will add one to the variable  
      x = 0
      x += 1
      x -= 1 will subtract one from the variable
      You can add any amount by adding an integer  +=3    
             e.g. x+=3 adds 3 to x every time the command executes.

3. There is a process called "TypeCasting". If there are two different variable types used in an equation Python will force them all to be floating point.   
           e.g. If x is an integer and y is a float z= x * y will result in z being a float answer.

4. Large numbers are written in Exponential Form.
          e.g. 20.12 raised to the power of 8 is written as 20.12E8

Practice Activity:

a = 10

a += 2


Notice that the new value will increase by 2.