NUMBERS AND FIGURES.

NUMBERS IN ENGLISH

21 → 99

Numbers between 21 to 99 should be hyphenated
21 : twenty-one
48 : forty-eight
92 : ninety-two

100 → 999

“ hundred” is invariable when preceded by a numeral.
100 : one hundred
200 : two hundred

“Two hundred people were there.”
But “Ø Hundreds of people were there.”

“and” or no “and”?

100 : a hundred / one hundred / a hundred (With large numbers it is usually one hundred ... but in other contexts a hundred ... is more natural.
101 : one hundred and one (UK) / one hundred one (US)
110 : one hundred and ten (UK) / one hundred ten (US)
200 : two hundred
201 : two hundred and one (UK) / two hundred one (US)
210 : two hundred and ten (UK) / two hundred ten (US)
…

1,000 → 9,999

“ thousand” is invariable when preceded by a numeral.
1,000 : one thousand
2,000 : two thousand

“Two thousand people were there.”
But “Ø Thousands of people were there.”

“and” or no “and”?

1,000 : one thousand
1,001 : one thousand and one (UK) / one thousand one (US)
1,010 : one thousand and ten (UK) / one thousand two (US)
1,100 : one thousand one hundred
1,110 : one thousand one hundred and ten (UK) / one thousand one hundred ten (US)


10,000 → 99,999

Basically it’s always the same as above.

10,000 : ten thousand
10,001 : ten thousand and one (UK) / ten thousand one (US)
10,010 : ten thousand and ten (UK) / ten thousand one (US)
10,100 : ten thousand one hundred
10,110 : ten thousand one hundred and ten (UK) / ten thousand one hundred ten (US)

100,000 → 999,999

100,000 : one hundred thousand
100,001 : one hundred thousand and one (UK) / one hundred thousand one (US)
100,010 : one hundred thousand and ten (UK) / one hundred thousand ten (US)
100,100 : one hundred thousand one hundred
101,000 : one hundred and one thousand (UK) / one hundred one thousand (US)
110,000 : one hundred and ten thousand (UK) / one hundred ten thousand (US)

1,000,000 → 999,999,999

“ million” is invariable when preceded by a numeral.

1,000,000 : one million
2,000,000 : two million

“This project cost two million dollars.”
But “This project cost Ø millions of dollars.”

1,000,000 : one million
1,000,001 : one million and one (UK) / one billion one (US)
1,000,010 : one million and ten (UK) / one billion ten (US)
1,000,100 : one million one hundred
1,001,000 : one million one thousand
1,010,000 : one million ten thousand
1,100,000 : one million one hundred thousand
1,110,000 : one million one hundred and ten thousand (UK) / one million one hundred ten thousand (US)
1,111,000 : one million one hundred and eleven thousand (UK) / one million one hundred eleven thousand (US)
1,111,100 : one million one hundred and eleven thousand one hundred (UK) / one million one hundred eleven thousand one hundred (US)
1,111,110: one million one hundred and eleven thousand one hundred and ten (UK) / one million one hundred eleven thousand one hundred ten (US)

1,000,000,000 and above

“ billion” is invariable when preceded by a numeral.

1,000,000,000 : one billion
2,000,000,000 : two billion

“This project cost two billion dollars.”
But “This project cost Ø billions of dollars.”

1,100,000,000 : one billion one hundred million
… (combine with what was said above)

Note:
Even in British English, “one billion” is now understood as one thousand million (1,000,000,000), not a million million (1,000,000,000,000).


Place of the commas and dots

The comma is used to separate thousands:
1,000 (one thousand)
45,000 (forty-five thousand)
100,000 (one hundred thousand)
1,000,000 (one million)
...

The dot is used to separate decimals
4.7 (four point seven)

→ 1,004.75