la unitati vom avea 0 , 1, 2, 3, 4, 5, 6, 7, 8, 9
la zeci numai 2
la sute vom avea 1, 2, 3, 4, 5, 6, 7, 8, 9,
120 , 121 , 122, 123, 124,125........129 = 9
220 , 221, 222.....................229=9
320 , 321, 322, 323..............329=9
.......................................
deci vom avea 9 x 9 = 81 de numere
