從左邊到右邊三個文本框的名稱依次是text1、text2、text3；
從上到下四個命令按鈕的名字依次是command1、command2、command3、command4。
private sub command1_click()
dim a as single,b as single,c as single
a=val(text1.text)
b=val(text2.text)
c=a+b
text3.text=str(c)
end sub
private sub command1_click()
dim a as single,b as single,c as single
a=val(text1.text)
b=val(text2.text)
c=a-b
text3.text=str(c)
end sub
private sub command1_click()
dim a as single,b as single,c as single
a=val(text1.text)
b=val(text2.text)
c=a*b
text3.text=str(c)
end sub
private sub command1_click()
dim a as single,b as single,c as single
a=val(text1.text)
b=val(text2.text)
c=a/b
text3.text=str(c)
end sub