四舍六入五留双规则当尾数小于或等于4时直接将尾数舍去当尾数大于或等于6时将尾数舍去向前一位进位当尾数为5而尾数后面的数字均为0时应看尾数5的前一位：若前一位数字此时为奇数就应向前进一位；若前一位数字此时为偶数则应将尾数舍去。数字0在此时应被视为偶数。当尾数为5而尾数5的后面还有任何不是0的数字时无论前一位在此时为奇数还是偶数也无论5后面不为0的数字在哪一位上都应向前进一位。 用英文

Rounding to the nearest even number rule When the decimal digit is less than or equal to 4, simply discard the decimal digit. When the decimal digit is greater than or equal to 6, discard the decimal digit and round up the previous digit. When the decimal digit is 5, and all the digits after 5 are 0, look at the digit before 5: if it is odd, round up; if it is even, discard the decimal digit. The digit "0" should be considered even in this case. When the decimal digit is 5, and there are any non-zero digits after 5, regardless of whether the digit before 5 is odd or even, and regardless of the position of the non-zero digit after 5, round up