Cardinal NumbersJust here for the exercises? Click here.
Cardinal numbers are basic numbers. We use them to count and to indicate how much of something there is.
Writing of Cardinal Numbers
In British English we put an and between the hundreds and the tens (110). If there are no tens (2,001), we put the and before the single digits. We can leave the and out in American English.
- 110 – one hundred and ten
(American English: one hundred ten)
- 1,250 – one thousand, two hundred and fifty
(American English: one thousand, two hundred fifty)
- 2,001 – two thousand and one
(American English: two thousand one)
We put a or one before the number 100, but only at the beginning of a number (a is colloquial).
- 100 – a hundred/one hundred
- 2,100 – two thousand, one hundred
Thousands and Millions
The same rule applies for a and one with thousands and millions as with hundreds.
- 1,000 - a thousand/one thousand
- 201,000 - two hundred and one thousand
Thousands are separated by commas in English.
- 57,458,302 – fifty-seven thousand, four hundred and fifty-eight thousand, three hundred and two
One Billion, Trillion etc.
The words billion, trillion etc. refer to different numbers in different languages. In English, one billion has 9 zeroes and one trillion has 12 zeroes.
- Example :
- one million = 1,000,000 (6 zeroes)
- one billion = 1,000,000,000 (9 zeroes)
- one trillion = 1,000,000,000,000 (12 zeroes)
- one quadrillion = 1,000,000,000,000,000 (15 zeroes)
- one quintillion = 1,000,000,000,000,000,000 (18 zeroes)