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unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

type
  TForm1 = class(TForm)
    Edit1: TEdit;
    Button1: TButton;
    Button2: TButton;
    Button3: TButton;
    Button4: TButton;
    Button5: TButton;
    Button6: TButton;
    Button7: TButton;
    Button8: TButton;
    Button9: TButton;
    Button10: TButton;
    Button11: TButton;
    Button12: TButton;
    Button13: TButton;
    Button14: TButton;
    Button15: TButton;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
    procedure Button6Click(Sender: TObject);
    procedure Button7Click(Sender: TObject);
    procedure Button8Click(Sender: TObject);
    procedure Button11Click(Sender: TObject);
    procedure Button12Click(Sender: TObject);
    procedure Button13Click(Sender: TObject);
    procedure Button4Click(Sender: TObject);
    procedure Button5Click(Sender: TObject);
    procedure Button9Click(Sender: TObject);
    procedure Button10Click(Sender: TObject);
    procedure Button14Click(Sender: TObject);
    procedure Button15Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
    TF,Signe,Erreur:Integer;
    N1,N2,N3:Real;
    S:String;
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
begin
    if (TF=0)then Edit1.Text:=Edit1.Text+'7'
             else begin
                   Edit1.Text:='7';
                   TF:=0;
                   end;


end;

procedure TForm1.Button2Click(Sender: TObject);
begin
  if (TF=0)then Edit1.Text:=Edit1.Text+'8'
             else begin
                   Edit1.Text:='8';
                   TF:=0;
                   end;
end;

procedure TForm1.Button3Click(Sender: TObject);
begin
   if (TF=0)then Edit1.Text:=Edit1.Text+'9'
             else begin
                   Edit1.Text:='9';
                   TF:=0;
                   end;
end;

procedure TForm1.Button6Click(Sender: TObject);
begin
   if (TF=0)then Edit1.Text:=Edit1.Text+'4'
             else begin
                   Edit1.Text:='4';
                   TF:=0;
                   end;
end;

procedure TForm1.Button7Click(Sender: TObject);
begin
  if (TF=0)then Edit1.Text:=Edit1.Text+'5'
             else begin
                   Edit1.Text:='5';
                   TF:=0;
                   end;
end;

procedure TForm1.Button8Click(Sender: TObject);
begin
   if (TF=0)then Edit1.Text:=Edit1.Text+'6'
             else begin
                   Edit1.Text:='6';
                   TF:=0;
                   end;
end;

procedure TForm1.Button11Click(Sender: TObject);
begin
      if (TF=0)then Edit1.Text:=Edit1.Text+'1'
             else begin
                   Edit1.Text:='1';
                   TF:=0;
                   end;
end;

procedure TForm1.Button12Click(Sender: TObject);
begin
      if (TF=0)then Edit1.Text:=Edit1.Text+'2'
             else begin
                   Edit1.Text:='2';
                   TF:=0;
                   end;
end;

procedure TForm1.Button13Click(Sender: TObject);
begin
    if (TF=0)then Edit1.Text:=Edit1.Text+'3'
             else begin
                   Edit1.Text:='3';
                   TF:=0;
                   end;
end;

procedure TForm1.Button4Click(Sender: TObject);
begin
   val(Edit1.Text,N1,Erreur);
   TF:=1;
   Signe:=1;
end;

procedure TForm1.Button5Click(Sender: TObject);
begin
   val(Edit1.Text,N1,Erreur);
   TF:=1;
   Signe:=2;
end;

procedure TForm1.Button9Click(Sender: TObject);
begin
     val(Edit1.Text,N1,Erreur);
   TF:=1;
   Signe:=3;
end;

procedure TForm1.Button10Click(Sender: TObject);
begin
   val(Edit1.Text,N1,Erreur);
   TF:=1;
   Signe:=4;
end;

procedure TForm1.Button14Click(Sender: TObject);
begin
   Edit1.Text:='';
   N1:=0;  
end;

procedure TForm1.Button15Click(Sender: TObject);
begin
   val (Edit1.Text,N2,Erreur);
   case Signe of
      1:N3:=N1/N2;
      2:N3:=N1*N2;
      3:N3:=N1+N2;
      4:N3:=N1-N2;
   end;
   Str(N3, Edit1.Text);
   Edit1.Text:=S;
   TF:=1;

end;

end.

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