import math


def round_number(number, significant_digits):
    """
    Rounds a number to the specified number of significant digits
    :param number: number to be rounded
    :param significant_digits: number of significant digits
    :return:
    """
    if number != 0:
        return round(number, significant_digits - int(math.floor(math.log10(abs(number)))) - 1)
    else:
        return 0