In this lesson, we’ll learn about fractional numerals. Fractional numerals (*quantificadores fraccionários*) define exact fractions, or parts, of a given thing. Let’s have a look at them.

Quantificador fraccionário |
Fractional numeral |
Quantificador fraccionário |
Fractional numeral |

meio/metade | half | dezasseis avos | sixteenth (part) |

terço | third | dezassete avos | seventeenth (part) |

quarto | fourth | dezoito avos | eighteenth (part) |

quinto | fifth | dezanove avos | nineteenth (part) |

sexto | sixth | vinte avos/vigésimo | twentieth (part) |

sétimo | seventh | trigésimo | thirtieth (part) |

oitavo | eighth | quadragésimo | fourtieth (part) |

nono | ninth | quinquagésimo | fiftieth (part) |

décimo | tenth | sexagésimo | sixtieth (part) |

onze avos/undécimo | eleventh (part) | septuagésimo | seventieth (part) |

doze avos/duodécimo | twelfth (part) | octogésimo | eightieth (part) |

treze avos | thirteenth (part) | nonagésimo | ninetieth (part) |

quatorze avos | fourteenth (part) | centésimo | hundredth (part) |

quinze avos | fifteenth (part) | milésimo | thousandth (part) |

Fractionals, just like multipliers, are paired with the preposition “de” or its prepositional contraction.

## Fractionals and Ordinary Numerals

You’ll notice that a lot of these fractional numerals (apart from meio/metade and terço) coincide with the masculine versions of ordinal numerals: *quarto, quinto, sexto, décimo, vigésimo*, etc. (This happens in English as well.) But when we want to express smaller and smaller fractions, we commonly use the feminine version of those ordinal numerals with the word “parte”, meaning “part” in English. Example:

Um **sétimo** destes impostos vai para caridade. One **seventh** of these taxes goes to charity.

But also

Uma **sétima parte** destes impostos vai para caridade. A **seventh part** of these taxes goes to charity.

Fractions must agree in number with the amount of parts being counted, as in English. So we could count a single seventh part as “um sétimo”, but two seventh**s** would be “dois sétimo**s**“, three seventh**s** would be “três sétimo**s**“, and so on.

## Using “Avos”

*Avos* is a funny little word in Portuguese that is used to signal every equal part a unit is divided in, as long as it’s divided more than ten times. Putting it another way: if we divide a certain something in ten equal parts or fewer, we use fractionals without “avo”. Example:

Um **quinto** dos estudantes copia em exames. A **fifth** of all students cheats during exams.

If we divide it into more than ten equal parts, we can use “avos”. Example:

Um **dezassete avos** dos estudantes copia em exames. **One seventeeth** of all students cheats during exames.

In the previous example, we used “avos” because we divided our student body into seventeen equal parts. Though “avos” can technically be used for any division beyond ten equal parts, it’s usually not used for multiples of ten. Example:

Vou dar-te **trinta avos** da minha herança. I’ll give you a **thirtieth part** of my inheritance.

But more commonly

Vou dar-te uma **trigésima parte** da minha herança. I’ll give you a **thirtieth part** of my inheritance.

Or

Vou dar-te um **trigésimo** da minha herança. I’ll give you one **thirtieth** of my inheritance.

Notice that, if we use the ordinary numeral + “parte” construction, “avos” is no longer used.

Usamos sempre **vinte e seis avos** do produto. We always use one **twenty-sixth part** of the product.

Or

Usamos sempre uma **vigésima-sexta parte** do produto. We always use one **twenty-sixth part** of the product.

not completely clear to me..if I want to say 2/5 ,16/17,35/117 how to say it..like if I am going to put this numbers in any mathematical equation how should I say?also use it any sentence to give example

Hello! Fractionals can be tricky indeed! The quick and easy rule is that, up to and including ten parts (X/10), you use cardinal numbers to count the amount of fractions, and ordinary numerals to tell how much of a fraction there is. In the case of 1/10, you’d say “um [1] décimo [10]” – “um” is the cardinal number, and “décimo” is an ordinary number; for 2/5, you’d say “dois[2] quintos[5]”; for 3/6, you’d say “três[3] sextos[6]”, and so on. After ten parts (x/11; x/12…x/100;…x/999) you use all cardinal numbers plus the word “avos”. So 4/60 would be “quatro[4] sessenta[60] avos”, for example; 5/34 would be “cinco[5] trinta e quatro[34] avos”. In Mathematics, after 10 parts, you always use “avos”. Hope that helps!