unit Cals; interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, Menus, StdCtrls; type TForm1 = class(TForm) mm1: TMainMenu; N1: TMenuItem; S1: TMenuItem; S2: TMenuItem; edt1: TEdit; Button1: TButton; Button2: TButton; Button3: TButton; Button4: TButton; Button5: TButton; Button6: TButton; Button7: TButton; Button8: TButton; Button9: TButton; Button11: TButton; Button12: TButton; Button13: TButton; Button14: TButton; Button15: TButton; Button16: TButton; Button18: TButton; Button19: TButton; Button20: TButton; Button21: TButton; Button22: TButton; Button23: TButton; Button25: TButton; Button26: TButton; Button27: TButton; Button28: TButton; Button29: TButton; Button30: TButton; edt2: TEdit; procedure Button19Click(Sender: TObject); procedure Button26Click(Sender: TObject); procedure Button1Click(Sender: TObject); procedure Button2Click(Sender: TObject); procedure Button3Click(Sender: TObject); procedure Button20Click(Sender: TObject); procedure Button21Click(Sender: TObject); procedure Button12Click(Sender: TObject); procedure Button13Click(Sender: TObject); procedure Button14Click(Sender: TObject); procedure Button5Click(Sender: TObject); procedure Button6Click(Sender: TObject); procedure Button7Click(Sender: TObject); procedure Button29Click(Sender: TObject); procedure Button30Click(Sender: TObject); procedure Button22Click(Sender: TObject); procedure Button15Click(Sender: TObject); procedure Button8Click(Sender: TObject); procedure Button27Click(Sender: TObject); procedure Button28Click(Sender: TObject); procedure Button9Click(Sender: TObject); procedure Button23Click(Sender: TObject); procedure UpdateDisplay(); procedure Calculate(); procedure OnOperandInput(a: Integer); procedure edt1KeyPress(Sender: TObject; var Key: Char); procedure FormCreate(Sender...