def use_pretty_numbers(enabled: bool=True):
    """Determine if problems should include only pretty numbers or 
    a whole range of integers and floats. Using pretty numbers will
    restrict the numbers that are generated to integers between 1 and
    12. When not using pretty numbers, floats and large integers will
    be included in the output from `rand_number`"""
    global _pretty_numbers
    _pretty_numbers = enabled
