unit Unit1;

{$mode objfpc}{$H+}

interface

uses

  Classes, SysUtils, FileUtil, Forms, Controls, Graphics, Dialogs, StdCtrls;

type

  { TForm1 }

  TForm1 = class(TForm)

    Button1: TButton;

    Button2: TButton;

    Button3: TButton;

    Button4: TButton;

    Edit1: TEdit;

    Edit2: TEdit;

    Edit3: TEdit;

    Memo1: TMemo;

    procedure Button1Click(Sender: TObject);

    procedure Button2Click(Sender: TObject);

    procedure Button3Click(Sender: TObject);

    procedure Button4Click(Sender: TObject);

  private

    { private declarations }

  public

    { public declarations }

  end;

var

  Form1: TForm1;

implementation

{$R *.lfm}

procedure TForm1.Button1Click(Sender: TObject);

var

  a, b, c: single;

begin

  a := StrToFloat(Edit1.Text);

  b := StrToFloat(Edit2.Text);

  c := a + b;

  Edit3.Text := FloatToStr(c);

  Memo1.Lines.Add(Edit1.Text + ' + ' + Edit2.Text + ' = ' + Edit3.Text);

end;

procedure TForm1.Button2Click(Sender: TObject);

var

  a, b, c: single;

begin

  a := StrToFloat(Edit1.Text);

  b := StrToFloat(Edit2.Text);

  c := a - b;

  Edit3.Text := FloatToStr(c);

  Memo1.Lines.Add(Edit1.Text + ' - ' + Edit2.Text + ' = ' + Edit3.Text);

end;

procedure TForm1.Button3Click(Sender: TObject);

var

  a, b, c: single;

begin

  a := StrToFloat(Edit1.Text);

  b := StrToFloat(Edit2.Text);

  c := a * b;

  Edit3.Text := FloatToStr(c);

  Memo1.Lines.Add(Edit1.Text + ' * ' + Edit2.Text + ' = ' + Edit3.Text);

end;

procedure TForm1.Button4Click(Sender: TObject);

var

  a, b, c: single;

begin

  a := StrToFloat(Edit1.Text);

  b := StrToFloat(Edit2.Text);

  c := a / b;

  Edit3.Text := FloatToStr(c);

  Memo1.Lines.Add(Edit1.Text + ' / ' + Edit2.Text + ' = ' + Edit3.Text);

end;

end.