Problem 4: Number of Six (100pts)

Write a function that takes a positive integer $n$ and returns the number of $6$ in each digit of it. (Using floor division and modulo might be helpful here!)

def number_of_six(n):
    """Return the number of 6 in each digit of a positive integer n.

    >>> number_of_six(666)
    3
    >>> number_of_six(123456)
    1
    """
    pass  # YOUR CODE HERE

Test your implementation with python ok -q number_of_six.