     print("You passed in a bad number")
 }
 /*:
-### Clean up after yourself
+Above ...
+*/
+/*:
+## Clean up after yourself
 
 */
 func createMyGrade(number: Int, letter: String) throws -> (Int, String)? {

printGrade((101, "A"))
printGrade((55, "E"))
printGrade((94, "A"))
/*:
## Error Handling


*/
/*:
## Guarding
A good practice when creating functions is to test that the inputs are valid. The `guard` statement is like an `if` statement except that a `guard` requires that you have an `else` for the false condition. If the `guard` statement evaluates to `false` the statements in the `else` are executed and *must* exit the function.
*/
func printGrade(grade: (Int, String)) {
    
