unit U_inicial;

interface

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Vcl.Buttons;

type
  TF_inicial = class(TForm)
    txt_visor: TEdit;
    btn_1: TSpeedButton;
    btn_2: TSpeedButton;
    btn_3: TSpeedButton;
    btn_6: TSpeedButton;
    btn_5: TSpeedButton;
    btn_4: TSpeedButton;
    btn_9: TSpeedButton;
    btn_8: TSpeedButton;
    btn_7: TSpeedButton;
    btn_0: TSpeedButton;
    btn_mult: TSpeedButton;
    btn_div: TSpeedButton;
    btn_som: TSpeedButton;
    btn_sub: TSpeedButton;
    btn_igua: TSpeedButton;
    btn_clea: TSpeedButton;
    procedure btn_0Click(Sender: TObject);
  private
    { Private declarations }
   var
   valor : Double;
   funcao : Char;

  public
    { Public declarations }
  end;

var
  F_inicial: TF_inicial;

implementation

{$R *.dfm}

procedure TF_inicial.btn_0Click(Sender: TObject);
begin
//Botao 0

   txt_visor.Text := txt_visor.Text = '0';

end;

end.