One-step method of mathematics means that some numbers can only appear in the form of integers in real life. For example, if there is 10 1 liter oil, it should be packed in small oil drums with a capacity of 20 liters respectively. How many small oil drums does a * * need? Use 10 1/20=5.05 small oil drum. According to the conventional rounding method, it is about equal to 5 small oil drums. But in fact, what we need is six small oil drums, because the remaining point needs one small oil drum, so it should be equal to six small oil drums. The tail was removed.

No matter how much is left, this method should be removed. For example, if there is 25m cloth, each set of children's clothing needs 2. 1m cloth. How many sets can a * * * make? So how many sets can be made is 25/2.1=1.90476 sets, which is equal to 12 sets according to the conventional method, but the remaining mantissa is not complete at all, so the truncation method can only be used to equal 1 1 sets.