Fix函数的具体用法,
Prirate sub Form__click( )
Dim R1 as double ,Dim R2 as Double
Dim Vol as Doubie
Const PI #=3.1415926
R1=10:R2=20
Vol=4/3*PI*(R1^3-R2^3)
Vol=Fix(Vol*10000+0.5)/10000
Print
Ned sub
求：fix函数的具体用法,为什么要写成Vol=Fix(Vol*10000+0.5)/10000.0.5为什么不写成0.