def add_digits(n):
    n = str(n)
    summ = 0
    for d in n:
        summ = summ + int(d)
    return summ

def digital_root(n):
    while n >=10:
        n = add_digits(n)
    return n

def is_digital_root(n, d):
    return digital_root(n) == d

def is_partial_add(n, p):
    while n >=10:
        n = add_digits(n)
        if n == p:
            return True
    return False