Perkalian Silang Contoh Kelima

ab * cd
= a * c | ( a * d ) + ( b * c ) | b * d

47 * 53
= 4 * 5 | ( 4 * 3 ) + ( 7 * 5 ) | 7 * 3
= 20 | 12 + 35 | 21
= 20 | 47 | 21
= 2 ( 0 + 4 ) | 7 + 2 | 1
= 2 4 9 1