Notam ordinele cu simboluri:
u - unitati, z - zeci, s - sute, M - mii, Z - zeci de mii
Z M s z u -Z M s z= 9 9 9 9 Z =1
Inlocuim u cifre: 0, 1, 2, .....9
1 1 1 1 0 2 2 2 2 1 3 3 3 3 2 1 1 1 0 9
Z M s z 0-
Z M s z 1- Z M s z 2- Z M s z 9
9 9 9 9 9
9 9 9 9 9
9 9 9 9 9 9
Z M s z Z M s
z Z M s z Z M s z
1 1 1 1 1 2 2
2 2 2 3 3 3 3 1 1 1 0
11110-1111=9999 11109=1110=9999
R. 11110; 11109