Numbers in Spanish: from 0 to a million, with the rules pupils get wrong

0 to 20

The pronunciation column follows the pronunciation of most of Spain, with the stressed syllable in capitals. In Latin America, the Canary Islands and parts of Andalusia, the “th” sound is an s: THEEN-koh becomes SEEN-koh.

From 16 to 29, numbers are written as one word: dieciséis, veintidós, veintitrés, veintiséis. Note the written accents on these four; the others in the series have none. The older separate spellings (“diez y seis”, “veinte y uno”) are now rare and should not be taught.

Tens and the numbers in between

From 31 onwards, y joins the tens and the units: cuarenta y dos, noventa y nueve. That is the only place y appears.

Tengo catorce años.I’m fourteen.

Un año tiene trescientos sesenta y cinco días.A year has three hundred and sixty-five days.

Son cuarenta y cinco euros.That’s forty-five euros.

Stress in the numbers follows regular rules, so the written accent is a reliable guide: dieciséis and veintitrés are stressed on the last syllable, veinte, treinta and cuarenta on the one before.

A memory trick for a classic confusion: sesenta (60) has an s like seis, setenta (70) has a t like siete.

Hundreds, thousands and millions

Three hundreds are irregular: quinientos, setecientos and novecientos (not “cincocientos”, “sietecientos”, “nuevecientos”).

Seven rules to know

1. Cien or ciento. Cien is 100 exactly, and is also used before a noun and before mil and millones: cien libros, cien mil. Ciento is used when more digits follow: ciento tres. Percentages use por ciento: el diez por ciento.
2. No “and” after hundreds. British English says “one hundred and three”; Spanish says ciento tres, never “ciento y tres”. Y only links tens and units.
3. Uno shortens before a masculine noun. un libro, veintiún años, treinta y un días. Before a feminine noun it becomes una: veintiuna chicas.
4. Hundreds agree in gender. doscientos chicos, doscientas chicas, quinientas libras.
5. Mil is invariable and never takes un. mil, dos mil, diez mil. “Un mil” is wrong.
6. Millón is a noun. It takes un, a plural and de before a noun: un millón de habitantes, tres millones de euros. The de disappears when more numbers follow: tres millones quinientos mil euros.
7. A billion is not un billón. English “billion” (a thousand million) is mil millones. Un billón is a million million.

Decimals, thousands and ordinals

In Spain the decimal marker is a comma: 3,5 is tres coma cinco. Mexico and several other Latin American countries use a point, as in the UK. For thousands, the Real Academia Española recommends a space rather than a point or comma, from five digits: 10 000. Pupils reading Spanish websites will meet all of these.

For mental maths in Spanish: más (plus), menos (minus), por (times), entre or dividido por (divided by), and son or es igual a (equals): Dos más tres son cinco. Useful words around numbers include la mitad (half), un tercio (a third), un cuarto (a quarter), una docena (a dozen) and un par (a pair, a couple).

The first ten ordinals are primero, segundo, tercero, cuarto, quinto, sexto, séptimo, octavo, noveno, décimo. Primero and tercero shorten before a masculine noun: el primer piso, el tercer día.

Typical mistakes of English-speaking learners

• Age with ser or estar: “soy doce años” or “estoy doce”. Age uses tener: Tengo doce años.
• “Ciento y uno”: a calque of “a hundred and one”. It is ciento uno.
• “Cien uno” or “un cien”: it is ciento uno and cien.
• “Veintiuno años”: before a masculine noun it is veintiún años.
• Missing accents: “dieciseis”, “veintitres”.
• Gender of hundreds: “doscientos libras” instead of doscientas libras.
• Sesenta and setenta swapped, especially in listening.
• Billion: translating “a billion” as un billón.

In class: a number routine

Numbers are forgotten fast if they are not used. Five numbers at the start of each lesson, of increasing difficulty, keep them alive all year.

1. Show a number in figures on the board.
2. The class says it aloud, all together or one pupil at a time.
3. Reveal the number written in words, so pupils can check spelling and accents.
4. Repeat with four more numbers, each a little harder than the last.
5. Now and then, reverse it: say a number, pupils write the figures on mini whiteboards.

This is exactly what a daily routine does: little, often, and slightly harder each time.

Useful variations: prices in euros (tres euros con cincuenta or tres cincuenta), phone numbers, football scores, the population of Spanish-speaking cities. At GCSE level, numbers in listening passages are a frequent stumbling block, so dictation of large numbers is time well spent.

Adapting to your class

• A10 to 100.
• A2Up to 1,000, with the hundreds and their agreement.
• B1Up to 100,000, with decimals: tres coma cinco.
• B2Up to 9,000,000, with millones de.

Frequently asked questions