9.  What is the value of the ASCII code for the character 
   ‘1’ minus the code for the character ‘0’? 
    What is ‘2’-‘0’? What does this say about converting 
    from the character form of a number into its numeric 
    value in general?

    code for '1' is 49 (base 10)
    code for '0' is 48

    '1' - '0' = 49 - 48 = 1

    code for '2' is 50
    code for '0' is 48

    '2' - '0' = 50 - 48 = 2

The number for any single digit character equals its 
ASCII code - the code for '0'
    