Unit 8.1
Cardinal numbers: Tens
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Introduction
Cardinal numbers give information about how many people or things there are.
Ten numbers go from 1 to 99.
Form
Ten numbers have ten as its base. However, the numbers from 1 to 9 are commonly called unities.
They have specific features:
- plain form: number + 0
- specific names from 0 to 20
- from 20 to 99 the numbers follow a pattern to name them: using a hyphen in between the ten number and the unit.
| Unities from 1 to 9 | Tens from 11 to 19 | Tens from 10 to 90 | Tens + unities |
| one | eleven | ten | twenty-one |
| two | twelve | twenty | twenty-two |
| three | thirteen | thirty | twenty-three |
| four | fourteen | fourty | twenty-four |
| five | fifteen | fifty | twenty-five |
| six | sixteen | sixty | twenty-six |
| seven | seventeen | seventy | twenty-seven |
| eight | eighteen | eighty | twenty-eight |
| nine | nineteen | ninety | twenty-nine |
NOTE: We normally use the singular form of the numbers when we are naming a concrete figure, while we use the plural form when we are not speaking about a concrete number, but in general terms.
Example
- 10 (ten)
- 25 (twenty-five)
Use
Tens numbers are used to measure, count, label things, codes from 1 to 99.
In formal writing it is better to write the number in letters when it is a short figure.
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