按照你字面意思，B1公式 : =A1-5*INT(A1/10)
=if(a1>=10,a1-floor(a1,10)/10*5,"")
=if(or(a1>10,a1<=20,a1-5,if(a1<=30,a1-10,if(a1<=40,a1-15,"")))
