A.擬舍棄數(shù)字最左一位數(shù)字小于5時(shí)，則舍棄
B.擬舍棄數(shù)字最左一位數(shù)字大于5時(shí)，則進(jìn)一
C.擬舍棄數(shù)字最左一位數(shù)字為5時(shí)，而后跟有非0數(shù)字時(shí)，則進(jìn)一
D.擬舍棄數(shù)字最左一位數(shù)字為5時(shí)，而后無數(shù)字或皆為0時(shí)，若保留的末位數(shù)為奇數(shù)時(shí)則進(jìn)一，為偶數(shù)時(shí)則舍棄
E.可連續(xù)修約