Cardinal Numbers 31–100 | Spanish (Latin America) Grammar

Once you pass treinta, Spanish numbers become remarkably predictable. From 31 to 99 you combine a round ten with a single digit, joined by the word y ("and"), and each part is written as a separate word. This is the opposite of the 16–29 rule, so pay close attention.

The round tens

Learn these nine words and you are most of the way there. Every number from 31 to 99 is built on one of them.

Number	Spanish
30	treinta
40	cuarenta
50	cincuenta
60	sesenta
70	setenta
80	ochenta
90	noventa
100	cien

Notice the spelling traps: cuarenta (not cuaranta), setenta (not sietenta), and noventa (not nuevainta). These forms do not follow the root vowels of their underlying digits.

Mi abuelo tiene setenta años.

My grandfather is seventy years old.

Combining tens and digits with y

To form any number from 31 to 99, write the round ten, then y, then the digit — three separate words.

Number	Spanish
31	treinta y uno
42	cuarenta y dos
55	cincuenta y cinco
67	sesenta y siete
78	setenta y ocho
89	ochenta y nueve
99	noventa y nueve

El libro cuesta cuarenta y cinco pesos.

The book costs forty-five pesos.

Somos treinta y dos personas en el grupo.

We are thirty-two people in the group.

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The one-word forms like treintaidós or cuarentaicinco do exist and are technically accepted, but they are rare in writing. Stick to the three-word form — it's the standard in Latin American textbooks, newspapers, and schools.

Uno still shortens

Just like with 21, the uno at the end of 31, 41, 51, and so on still drops its -o before a masculine noun and becomes una before a feminine noun.

Form	Context	Example
uno	alone, counting	treinta y uno
un	before masc. noun	treinta y un libros
una	before fem. noun	treinta y una mesas

Hay cincuenta y un estudiantes inscritos.

There are fifty-one students enrolled.

La biblioteca tiene sesenta y una sillas nuevas.

The library has sixty-one new chairs.

For a review of this shortening rule at lower numbers, see Cardinal Numbers 0–30.

Reaching 100: cien vs ciento

The number 100 has two forms, and choosing between them is one of the most common stumbling points for learners.

Use cien for exactly 100, or when the number stands alone as "one hundred" directly before a noun.
Use ciento when 100 is followed by a smaller number (101, 125, 199...).

Form	When	Example
cien	exactly 100, counting	cien pesos
cien	before mil / millón	cien mil
ciento	101–199	ciento cinco

Tengo cien dólares en el bolsillo.

I have one hundred dollars in my pocket.

El examen tiene ciento veinte preguntas.

The test has one hundred and twenty questions.

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Notice that Spanish does not insert y between 100 and the next number. It's ciento cinco, not ciento y cinco. The y only appears between the tens and units of a number — between 100 and the tens there is nothing.

Putting it all together

Here are some realistic mid-range numbers you're likely to use when shopping, giving an age, or talking about quantities.

Mi mamá cumple cuarenta y siete años mañana.

My mom turns forty-seven tomorrow.

La maratón tiene noventa y ocho corredores registrados.

The marathon has ninety-eight registered runners.

Stress and pronunciation

When you read these numbers aloud, notice that the stress falls on the second-to-last syllable of each round ten: cua-*ren-ta, cin-**cuen-ta, se-**sen-ta, and so on. The little word *y is unstressed and almost swallowed in fast speech, so cincuenta y cinco often sounds like cincuentaicinco. This is normal — don't try to pause on the y.

Son las tres y cuarenta y cinco de la tarde.

It is three forty-five in the afternoon.

Also worth noting: numbers never carry a written accent in this range. Cuarenta, cincuenta, sesenta, setenta, ochenta, and noventa are all written without a tilde. The written-accent headaches really only apply to 16–29 and to the hundreds like veintidós.

A final drill

Try reading these aloud to check yourself. Each one hides a common trap: the shortening of uno, the y conjunction, a tricky tens spelling, or the cien/ciento choice.

Ochenta y un pasajeros esperan en la puerta.

Eighty-one passengers are waiting at the gate.

Noventa y nueve globos rojos flotaban en el cielo.

Ninety-nine red balloons were floating in the sky.

If you can say each of those without hesitating, you've mastered the 31–100 range.

Practice saying each number aloud. Spanish speakers rarely pause between treinta, y, and cinco — the three words flow together like one long word. Once you reach 100, the numbering system scales quickly. Continue with Cardinal Numbers 100 and Beyond to learn the hundreds, thousands, and millions.