| Cardinal number | Portuguese | PT–BR | PT–PT |
| 0 | zero | ||
| 1 | um | ||
| 2 | dois | ||
| 3 | três | ||
| 4 | quatro | ||
| 5 | cinco | ||
| 6 | seis * | ||
| 7 | sete | ||
| 8 | oito | ||
| 9 | nove | ||
| 10 | dez | ||
| 11 | onze | ||
| 12 | doze | ||
| 13 | treze | ||
| 14 | catorze ** | ||
| 15 | quinze | ||
| 16 | dezesseis (br) / dezasseis (pt) | ||
| 17 | dezessete (br) / dezassete (pt) | ||
| 18 | dezoito | ||
| 19 | dezenove (br) / dezanove (pt) | ||
| 20 | vinte |
* In Brazil, “meia” (from meia dúzia = half a dozen) is frequently used to replace “seis” when spelling a large number such as telephone number or IDs. Mainly, this is to avoid confusion with the number three (três, seis sound similar in noisy environments)
** quatorze is also right and is the most used form in Brazil. But people pronounce it exactly the same way as catorze.