FLOOR function

'''Rounds a number down toward zero significance. If the sign of number is positive, a value is rounded down and adjusted toward zero. If the sign of number is negative, a value is rounded down and adjusted away from zero. If number is an exact multiple of significance, no rounding occurs.'''


 * If either argument is nonnumeric, FLOOR returns the #VALUE! error value.
 * If number is positive and significance is negative, FLOOR returns the #NUM! error value.