Build a function, do_math, that takes in 3 parameters: num1 (number), num2 (number), and operator (string)
- it uses the operator to determine what math to do to the numbers
- if '+', it adds them
- if '-', it subtracts them
- if '*' or 'x' or 'X', it multiplies them
- if '/', it divides them
- if then returns the result
- Example:
- do_math(5,2,'*')
- Return: 10