 
Table de Pythagore pour l'addition en base neuf
| + | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 10 | 
|---|---|---|---|---|---|---|---|---|---|---|
| 0 | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 10 | 
| 1 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 10 | 11 | 
| 2 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 10 | 11 | 12 | 
| 3 | 3 | 4 | 5 | 6 | 7 | 8 | 10 | 11 | 12 | 13 | 
| 4 | 4 | 5 | 6 | 7 | 8 | 10 | 11 | 12 | 13 | 14 | 
| 5 | 5 | 6 | 7 | 8 | 10 | 11 | 12 | 13 | 14 | 15 | 
| 6 | 6 | 7 | 8 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 
| 7 | 7 | 8 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 
| 8 | 8 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 
| 10 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 20 |