[NumLock]

можно еще IScriptControl использовать:

Код:

program Project1;

{$APPTYPE CONSOLE}

uses
  ActiveX,
  ComObj,
  MSScriptControl in 'MSScriptControl.pas';

var
  ScriptControl: IScriptControl;
  Expression: OleVariant;
  Eval: String;

begin
  Expression:='Math.sqrt(9)*5+85';
  OleInitialize(nil);
  ScriptControl:=CreateComObject(CLASS_ScriptControl) as IScriptControl;
  ScriptControl.Language:='javascript';
  Eval:=ScriptControl.Eval(Expression);
  Writeln(Expression+' = '+Eval);
  Readln;
end.