I tried this code, working good
Sub Globals
Dim EditText1 As EditText
Dim EditText2 As EditText
Dim EditText3 As EditText
Dim Button1 As Button
Dim A,B,C As Int
Dim D As Float
'These global variables will be redeclared each time the activity is created.
End Sub
Sub Activity_Create(FirstTime As Boolean)
Activity.LoadLayout("Layout")
End Sub
Sub Activity_Resume
End Sub
Sub Activity_Pause (UserClosed As Boolean)
End Sub
Sub Button1_Click
A = EditText1.Text
B = EditText2.Text
C= Power (10,B)
D=A/C
EditText3.Text = D
End Sub