Using unos, unas + number = about/approximately

If unos/unas is used before a number, it usually means "about""some" or "approximately". Like adjectives, the article must agree with the noun in number and gender.
 
For example: 

La película dura unos ochenta minutos.
The film lasts about eighty minutes.

El taxi tardó unos veinte minutos.
The taxi took about twenty minutes.

Tengo unos cincuenta euros en la cartera.
I have about fifty euros in the wallet.

In the examples above, the number is invariable and it never changes its form.

Now, look at these examples:

Elías tenía unas cuatrocientas libras en el banco.
Elías had about four hundred pounds in the bank.

El viaje ha sido unos doscientos kilómetros.
The trip was approximately two hundred kilometers.

Note that in the examples above, the whole hundreds from 200 onwards (200, 300, 400, 500, 600, etc.) agree with the noun they precede. Be careful because with other hundreds like 203, 345, etc., the tens and units do not change, just the hundreds.

For example:

Había unas quinientas treinta y cuatro especies en peligro de extinción.
There were about five hundred and thirty-four species in danger of extinction.

See also Using plural definite article + number + noun and Using numbers + nouns

Learn more about these related Spanish grammar topics

Examples and resources

El taxi tardó unos veinte minutos.
The taxi took about twenty minutes.


Tengo unos cincuenta euros en la cartera.
I have about fifty euros in the wallet.


El viaje ha sido unos doscientos kilómetros.
The trip was approximately two hundred kilometers.


Elías tenía unas cuatrocientas libras en el banco.
Elías had about four hundred pounds in the bank.


La película dura unos ochenta minutos.
The film lasts about eighty minutes.


Había unas quinientas treinta y cuatro especies en peligro de extinción.
There were about five hundred and thirty-four species in danger of extinction.


Q&A

Alan

Kwiziq community member

24 December 2018

1 reply

Would it be right to say "unas cuatro libras" - "about 4 pounds"

Inma

Kwiziq language super star

24 December 2018

24/12/18

Hola Alan

Yes, that'd be correct.

:))

Getting that for you now.