For example, the result of dividing -3 by 2 should be-1.5, but the result after rounding to 0 is-1 (not -2, because-1 is closer to 0). If 3 is divided by 2 and rounded to 0, the result is 1. That is to say, the original calculated number is selected according to the principle of approaching 0. Don't follow the rounding.