(i) 548 x 98
= (500 + 40 + 8) x 98
= 500 x 98 + 40 x 98 + 8 x 98
= 49000 + 3920 + 784 = 53704
(ii) 924 x 988
= (900 + 20 + 4) x 988
= 900 x 988 + 20 x 988 + 4 x 988
= 889200 + 19760 + 3952 = 912912
(iii) 3023 x 723
= (3000 + 20 + 3) x 723
= 3000 x 723 + 20 x 723 + 3 x 723
= 2169000 + 14460 + 2169 = 2185629
