| 1. | primero, -a |
| 2. | segundo, -a |
| 3. | tercero, -a |
| 4. | cuarto, -a |
| 5. | quinto, -a |
| 6. | sexto, -a |
| 7. | séptimo, -a |
| 8. | octavo, -a |
| 9. | noveno, -a |
| 10. | décimo, -a |
Note that the order numbers have both masculine and feminine forms. The numbers primero (first) and tercero (third) are shortened to primer and tercer when they precede a singular masculine noun.
Este es mi primer viaje a Francia.
This is my first trip to France.
El miércoles es el tercer día de la semana.
Wednesday is the third day of the week.
In most cases, order numbers greater than 10th are not used, but are expressed by the corresponding basic number, which is placed after the noun:
el piso trece
the 13th / thirteenth floor
el aniversario cincuenta
the 50th / fiftieth anniversary