Why do we need Functions?

[mnrvovrfc]

SUB Arrotonda! (num!)
    Arrotonda! = _ROUND(num! * 100) / 100
END SUB

because the "!" is not admited and, without the "!", we will have:

SUB Arrotonda (num!)
    Arrotonda = _ROUND(num! * 100) / 100
END SUB

This is incorrect syntax either way because the name of the "SUB" cannot be used in assignment. Must be a "FUNCTION" instead.