When the rounded number is equal to 5 and there is no number after 5 that is not "0", it depends on the number before 5.
- If it is an odd number, it will be rounded up, if it is an even number, 5 will be rounded off, that is, the last number will become an even number after the rounding;
If there is any number that is not "0" after 5, then no matter whether the front of 5 is odd or even, carry should be carried out.
From a statistical point of view, "rounding up to five" is more scientific than "rounding", which makes some rounded results larger, some smaller, and more average. Instead of rounding every five like "rounding", the result is biased towards large numbers.