(i) 505 x 503 = (500 + 5) (500 + 3)
                    = 500² + (5 + 3) (500) + 5 x 3
                    = 250000 + 4000 + 15 = 254015
(ii) 37 x 26 = (30 + 7) (30 - 4)
                 = 30² + (7 - 4) (30) - 7 x 4
                 = 900 + 90 - 28 = 962