Cardinal numbers are the numbers used for expressing quantity (cantidad), such as one, two, three, and so on.
0 – 10
| cero | zero |
| uno | one |
| dos | two |
| tres | three |
| cuatro | four |
| cinco | five |
| seis | six |
| siete | seven |
| ocho | eight |
| nueve | nine |
| diez | ten |
11 – 19
| once | eleven |
| doce | twelve |
| trece | thirteen |
| catorce | fourteen |
| quince | fifteen |
| dieciséis | sixteen |
| diecisiete | seventeen |
| dieciocho | eighteen |
| diecinueve | nineteen |
20 – 29
There are two ways to say the numbers 21 through 29, either as veinti + the ones digit, and all one word, for example, veintisiete, or as veinte y + the ones digit (separate words), for example, veinte y siete. I prefer the one word way, and I think that way is more common, though both are okay.
| veinte | twenty | |
| veintiuno | veinte y uno | twenty one |
| veintidos | veinte y dos | twenty two |
| veintitres | veinte y tres | twenty three |
| veinticuatro | veinte y cuatro | twenty four |
| veinticinco | veinte y cinco | twenty five |
| veintiseis | veinte y seis | twenty six |
| veintisiete | veinte y siete | twenty seven |
| veintiocho | veinte y ocho | twenty eight |
| veintinueve | veinte y nueve | twenty nine |
30 – 99
The numbers 30 through 99 all follow the same pattern, which is tens place number plus y plus ones place number, separated by spaces. For example, forty four is cuarenta y cuatro.
100 – 999
100 is said as cien, but any number from 101 through 199 is said as ciento followed by a space and then the number without the hundreds place. For example, 170 is said as ciento setenta. The names of numbers from 200 through 999 follow a similar pattern, except some word ending in cientos is used, although for 500 through 599 the word quinientos is used, as quinientos is the word for 500. Por ejemplos, two hundred is doscientos, two hundred twenty five is doscientos veinticinco, and nine hundred ninety nine is novecientos noventa y nueve.
1000+
One thousand is simply mil, and for multiples of one thousand that are less than one million, you say the number of thousands followed by the word mil. For example, ten thousand is diez mil. A similar pattern is in place with the words for millions, trillions, and so on, with the exception of the word for billion, which is mil millones. The Spanish word billón is a false cognate, it actually means trillion. Por ejemplos, one hundred million is cien millones, and three billion is tres mil millones.
A note on using a number as an adjective (stating the number of items)
When stating the count of an item followed by the word for that item, the ending of numbers that end in o or os may change to a or as if the tens place and the ones place are both zero. For example, two hundred plates is doscientos platos, while two hundred chairs is doscientas sillas, but two hundred ten chairs is doscientos diez sillas. Another rule is that when the number used as an adjective ends in one, and the word of what is being counted is masculine, then the o is simply left off. For example, twenty one hats is veintiún sombreros, eighty one points is cuarenta y un puntos, and one table is una mesa. If you are simply saying the number, and the ones digit is 1, then uno is used.
En conclusión
Counting in Spanish isn’t so bad. There are some patterns to memorize, but as usual, with practice you will get good at saying numbers in Spanish.