Excel中保留有效数字的问题

在工作表界面中按 <alt>+<F11>,
进入代码页面，然后再 WORKBOOK中插入模块，把以下代码COPY入模块中。
就可以在工作表中使用 =YXSZ(数值，保留位数）。

如：
A1=456.789
B1=YXSZ(A1,4）
  =456.8

代码如下：

Public Function YXSZ(X, n As Integer)  'n为有效数字位数

    Dim jk, j
    Dim Y As Single
    Dim temp As String
    Dim zfh As Integer
    zfh =
    If X = "" Or (Not Application.WorksheetFunction.IsNumber(X)) Then mYX = "?Value!": Exit Function
    X = Val(X)

    If n <  Then mYX = X: Exit Function
    If X <=  Then
        zfh = -
        X = X * zfh
    End If
    If X <  Then
        j = 

        Do
            temp = CStr(X)
            j = j +
        Loop Until Val(Mid$(temp, j, )) >
        j = j + n
        X = X *  ^ j
        jk = Len(CStr(Int(X))) - n
        Y = X /  ^ jk + 0.5
        YXSZ = Int(Y) *  ^ jk /  ^ j* zfh
        X = X /  ^ j 

    Else
        jk = Len(CStr(Int(X))) - n
        Y = X /  ^ jk + 0.5
        YXSZ = Int(Y) *  ^ jk * zfh
    End If

End Function