Option Explicit
Dim WshShell, theCalculator
Dim a, a1, a2

Set WshShell = WScript.CreateObject("WScript.Shell")
a = InputBox(a, "Enter first  operand")
a2 = InputBox(a2, "Enter sign")
a1 = InputBox(a1, "Enter second operand")

Set theCalculator = WshShell.Exec("calc")

WScript.Sleep 500
WshShell.AppActivate theCalculator.ProcessID

WScript.Sleep 500

Select Case a2

Case "+"
WshSHell.SendKeys a & "{+}"
Case "-"
WshSHell.SendKeys a & "{+}"
Case "/"
WshSHell.SendKeys a & "{/}"
Case "*"
WshSHell.SendKeys a & "{*}"

end select
WScript.Sleep 100

WshShell.SendKeys a1

WScript.Sleep 100

WshShell.SendKeys "~"

WScript.Sleep 100

WshShell.SendKeys "^c"

WScript.Sleep 100

WshShell.AppActivate theCalculator.ProcessID

WshShell.SendKeys "%{F4}"

WshShell.Run "notepad"

WScript.Sleep 1000

WshShell.AppActivate "notepad"

WshShell.SendKeys a

If a2="+" then
WshSHell.SendKeys "{+}"
else
WshShell.SendKeys a2
End If

WshShell.SendKeys a1 & "="
WshShell.SendKeys "^v"