[NumLock]

Код:

unit Unit1;

interface

uses
  MSHTML,
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  StdCtrls, ExtCtrls, OleCtrls, SHDocVw;

type
  TFormMain = class(TForm)
    WebBrowser: TWebBrowser;
    Panel: TPanel;
    Edit: TEdit;
    Button: TButton;
    Memo: TMemo;
    procedure ButtonClick(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  FormMain: TFormMain;

implementation

{$R *.dfm}

procedure TFormMain.ButtonClick(Sender: TObject);
begin
  WebBrowser.Navigate('about:blank');
  while WebBrowser.ReadyState<READYSTATE_INTERACTIVE do
    Application.ProcessMessages;
  (WebBrowser.Document as IHTMLDocument2).body.innerText:='';
  (WebBrowser.Document as IHTMLDocument2).parentWindow.execScript('var r=3434+56-676*45; document.write(r);', 'javascript');
  Memo.Lines.Insert(0, (WebBrowser.Document as IHTMLDocument2).body.innerText);
end;

end.

естественно поддерживаются все математические функции.