请VB高手来，为什么百分比计算老出错

我是VB新手 制了一个百分比计算器 可是输入数据相差大一点就计算出错,请高手帮我看一下，最好帮我改改语句,我设计的是上面3个框输入数字计算结果在下面三个框中显示。
Private Sub Command1_Click()
Dim a As Double
Dim b As Double
Dim c As Double
Let a=Val (Text1.Text)
Let b=Val (Text2.Text)
Let c=Val (Text3.Text)
Text4.Text=a/(a+b+c)
Text5.Text=b/(a+b+c)
Text6.Text=c/(a+b+c)

改为如下代码：
Private Sub Command1_Click()
Dim a As Double
Dim b As Double
Dim c As Double
Let a = Val(Text1.Text)
Let b = Val(Text2.Text)
Let c = Val(Text3.Text)
Text4.Text = (Int(10000 * a / (a + b + c)) / 100) & "%"
Text5.Text = (Int(10000 * b / (a + b + c)) / 100) & "%"
Text6.Text = (Int(10000 * c / (a + b + c)) / 100) & "%"
If Len(Text4.Text) < 5 Then Text4.Text = "0" & Text4.Text
If Len(Text5.Text) < 5 Then Text5.Text = "0" & Text5.Text
If Len(Text6.Text) < 5 Then Text6.Text = "0" & Text6.Text
End Sub

private sub command1_click() msgbox "百分比为：" & format(text1 * 100 / text2, "00.00") & "%" end sub text1 text2中输入数字，分别为分子和分母

Private Sub Command1_Click() Dim a As Double Dim b As Double Dim c As Double Let a = Val(Text1.Text) Let b = Val(Text2.Text) Let c = Val(Text3.Text) If a + b + c <> 0 Then Text4.Text = a / (a + b + c) Text5.Text = b / (a + b + c) Text6.Text = c / (a + b + c) End If End Sub

有可能是你将数据定义为double求解容易产生溢出错误导致结果错误。改为float即可。即 Private Sub Command1_Click() Dim a As float Dim b As float Dim c As float Let a=Val (Text1.Text) Let b=Val (Text2.Text) Let c=Val (Text3.Text) Text4.Text=a/(a+b+c) Text5.Text=b/(a+b+c) Text6.Text=c/(a+b+c)