ayuda con calculadora

[chelo_lpa]

unit Calculadora1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, RpDefine, RpRender, RpRenderPDF, Grids, Calendar, ExtCtrls, DBGrids,
  DB, DBTables, ComCtrls, StdCtrls, jpeg, OleCtrls, SHDocVw, IdBaseComponent,
  IdComponent, IdIPWatch;

type
  TForm1 = class(TForm)
    Edit1: TEdit;
    Edit2: TEdit;
    Edit3: TEdit;
    Edit4: TEdit;
    Edit5: TEdit;
    Edit6: TEdit;
    Edit7: TEdit;
    Edit8: TEdit;
    Edit9: TEdit;
    Edit10: TEdit;
    Edit11: TEdit;
    Edit12: TEdit;
    Edit13: TEdit;
    Edit14: TEdit;
    Edit15: TEdit;
    Edit16: TEdit;
    Edit17: TEdit;
    Edit18: TEdit;
    Edit19: TEdit;
    Edit20: TEdit;
    Edit21: TEdit;
    Edit22: TEdit;
    Edit23: TEdit;
    Edit24: TEdit;
    Edit25: TEdit;
    Edit26: TEdit;
    Edit27: TEdit;
    Edit28: TEdit;
    Edit29: TEdit;
    Edit30: TEdit;
    Edit31: TEdit;
    Button1: TButton;
    Calculadora: TLabel;
    Label2: TLabel;
    Label3: TLabel;
    Label4: TLabel;
    Label5: TLabel;
    Label6: TLabel;
    Label7: TLabel;
    Label8: TLabel;
    Label9: TLabel;
    Label10: TLabel;
    Label1: TLabel;
    Label11: TLabel;
    Label12: TLabel;
    Label13: TLabel;
    Label14: TLabel;
    Label15: TLabel;
    Label16: TLabel;
    Label17: TLabel;
    Label18: TLabel;
    Label19: TLabel;
    Label20: TLabel;
    Recordatorio: TMemo;
    DateTimePicker1: TDateTimePicker;
    Memo1: TMemo;
    Label21: TLabel;
    enREDados: TLabel;
    Label22: TLabel;
    Label23: TLabel;
    procedure Edit1KeyPress(Sender: TObject; var Key: Char);
    procedure Edit30Change(Sender: TObject);
    procedure FormActivate(Sender: TObject);
    procedure Edit2Change(Sender: TObject);
    procedure Edit3Change(Sender: TObject);
    procedure Edit6Change(Sender: TObject);
    procedure Edit7Change(Sender: TObject);
    procedure Edit9Change(Sender: TObject);
    procedure Edit12Change(Sender: TObject);
    procedure Edit14Change(Sender: TObject);
    procedure Edit15Change(Sender: TObject);
    procedure Edit17Change(Sender: TObject);
    procedure Edit19Change(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var

  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Edit12Change(Sender: TObject);
begin
    if((Edit11.Text <> ('')) and (Edit12.Text <> ('')))then
        Edit26.Text := IntToStr((StrToInt(Edit12.Text)*(StrToInt(Edit11.Text))))
    else
        Edit26.Text := IntToStr(0);
end;

procedure TForm1.Edit14Change(Sender: TObject);
begin
    if((Edit13.Text <> ('')) and (Edit14.Text <> ('')))then
        Edit27.Text := IntToStr((StrToInt(Edit13.Text)*(StrToInt(Edit14.Text))))
    else
        Edit27.Text := IntToStr(0);
end;

procedure TForm1.Edit15Change(Sender: TObject);
begin
    if((Edit15.Text <> ('')) and (Edit16.Text <> ('')))then
        Edit28.Text := IntToStr((StrToInt(Edit15.Text)*(StrToInt(Edit16.Text))))
    else
        Edit28.Text := IntToStr(0);
end;

procedure TForm1.Edit17Change(Sender: TObject);
begin
    if((Edit17.Text <> ('')) and (Edit18.Text <> ('')))then
        Edit29.Text := IntToStr((StrToInt(Edit17.Text)*(StrToInt(Edit18.Text))))
    else
        Edit29.Text := IntToStr(0);
end;

procedure TForm1.Edit19Change(Sender: TObject);
begin
    if((Edit19.Text <> ('')) and (Edit20.Text <> ('')))then
        Edit30.Text := IntToStr((StrToInt(Edit19.Text)*(StrToInt(Edit20.Text))))
    else
        Edit30.Text := IntToStr(0);
end;

procedure TForm1.Edit1KeyPress(Sender: TObject; var Key: Char);
begin
  if not ((Key in ['0'..'9'] )or (Key = #08)) then
    begin
      Key:= #0;
      Beep;
    end;

end;

procedure TForm1.Edit2Change(Sender: TObject);
begin
    if((Edit1.Text <> ('')) and (Edit2.Text <> ('')))then
        Edit21.Text := IntToStr((StrToInt(Edit2.Text)*(StrToInt(Edit1.Text))))
    else
        Edit21.Text := IntToStr(0);
end;

procedure TForm1.Edit30Change(Sender: TObject);
var
  a , I: integer;
begin
  a:=0;
  for I := 21 to 30 do
     if(((FindComponent('Edit' + IntToStr(i)) as TEdit).Text))<>('')then
        begin
            a:=a + (  StrToInt((FindComponent('Edit' + IntToStr(i)) as TEdit).Text));
        end
     else
        a:=a+0;
  Edit31.Text := IntToStr(a);
end;

procedure TForm1.Edit3Change(Sender: TObject);
begin
    if((Edit3.Text <> ('')) and (Edit4.Text <> ('')))then
        Edit22.Text := IntToStr((StrToInt(Edit3.Text)*(StrToInt(Edit4.Text))))
    else
        Edit22.Text := IntToStr(0);
end;

procedure TForm1.Edit6Change(Sender: TObject);
begin
    if((Edit5.Text <> ('')) and (Edit6.Text <> ('')))then
        Edit23.Text := IntToStr((StrToInt(Edit5.Text)*(StrToInt(Edit6.Text))))
    else
        Edit23.Text := IntToStr(0);

end;

procedure TForm1.Edit7Change(Sender: TObject);
begin
    if((Edit7.Text <> ('')) and (Edit8.Text <> ('')))then
        Edit24.Text := IntToStr((StrToInt(Edit7.Text)*(StrToInt(Edit8.Text))))
    else
        Edit24.Text := IntToStr(0);

end;

procedure TForm1.Edit9Change(Sender: TObject);
begin
    if((Edit9.Text <> ('')) and (Edit10.Text <> ('')))then
        Edit25.Text := IntToStr((StrToInt(Edit9.Text)*(StrToInt(Edit10.Text))))
    else
        Edit25.Text := IntToStr(0);

end;

procedure TForm1.FormActivate(Sender: TObject);
var
  i, a: Integer;
begin
 for i := 1 to 20 do
  begin
    if ((i mod 2)= 0) then
      begin
        (FindComponent('Edit' + IntToStr(i)) as TEdit).text := '1';
      end
    else
      begin
       (FindComponent('Edit' + IntToStr(i)) as TEdit).text := '0';
      end;
  end;
  for a := 21 to 30  do
   (FindComponent('Edit' + IntToStr(a)) as TEdit).text := '0';
end;





end.

asi me qedo el codigo. anda todo de diez hace lo que quiero. ahora es el tema donde tengo una duda...
$1
eso es un peso, pero yo quiero mostrarlo asi
1.00
y asi con tengo qe encontrar lamanera de acceder a los ultimos dos caracteres de mi string, correrlos un lugar para la derecha y agregar la coma donde estaba el anteultimo. bien se qe un string es un array of caracteres. tendria qe acceder por array size. existe una funcion asi? y hay alguna manera de aumentar el array en ese momento? sigo probando y leyendo.