Title: Find factorial value
This example shows how to get factorial value for all numbers in [1, 30] interval
procedure TForm1.Button1Click(Sender: TObject);
var
i: Integer;
Num: Real;
begin
Num:=1;
for i:=1 to 30 do
begin
Num:=Num*i;
Memo1.Lines.Add(IntToStr(i)+'! = '+FloatToStr(Num));
end;
end;