def find_largest_digit_helper(max_digit, current):
	"""
	This function will help the user find the largest digit in a certain number
	by continuously dividing 10 to get every digit within the number.
	:param max_digit: int, An initial value for comparison.
	:param current: int, Each digit found in a certain number.
	:return: int, The largest digit found in a certain number after checking all digits within the number.
	"""
	if current == 0:
		# Return the largest digit after all digits has been cross-compared.
		return max_digit
	else:
		# Get each digit.
		digit = current % 10
		# Compare the obtained digit with the current max_digit.
		if digit > max_digit:
			max_digit = digit
		# Delete the last digit for the next round of comparison
		current = current // 10
		return find_largest_digit_helper(max_digit, current)