12進数は掛け算の表が作りやすいので経済的

 1, 2, 3, 4, 5, 6, 7, 8, 9, a, b
 2, 4, 6, 8, a,10,12,14,16,18,1a
 3, 6, 9,10,13,16,19,20,23,26,29
 4, 8,10,14,18,20,24,28,30,34,38