Large numbers are numbers bigger than the basic counting range, especially from 100 onward. In English, you build them by combining hundreds, thousands, millions, and so on in a fixed order. This module teaches how to say, read, and write large numbers clearly, including key differences between American and British usage.

English groups digits into threes from the right when naming large numbers. Each group has a name such as thousand, million, or billion, and you say the highest group first, then move down. Understanding the groups helps you avoid skipping or repeating a scale word.

Word/Phrase	Definition	Example
ones	the last digit group, up to 9	7 is seven
tens	the second digit place, 10 to 99	42 is forty-two
hundreds	the third digit place, 100 to 999	600 is six hundred
thousand	1,000 to 999,999	12,000 is twelve thousand
million	1,000,000 to 999,999,999	3,000,000 is three million
billion	1,000,000,000 to 999,999,999,999	5,000,000,000 is five billion

Scale words name each 3-digit group: thousand, million, billion, and beyond. You do not pluralize a scale word when a number comes directly before it. You typically omit the word one before hundred and thousand in neutral speech, but it can be included for emphasis or clarity.

Rule	Example
Say groups from largest to smallest scale word	2,040,000 is two million forty thousand
Do not add s to scale words after a number	6 million, not 6 millions
Use a scale word only if that 3-digit group is not zero	7,000,005 is seven million five
One hundred is common; a hundred is also natural	100 is one hundred or a hundred

For 100–999, English uses the pattern number plus hundred, then the rest of the number. In American English, it is common to say the remaining part directly after hundred without and. In British English, and is commonly used before the tens and ones part.

Rule	Example
Pattern: digit + hundred + remaining number	342 is three hundred forty-two
US: and is usually omitted	115 is one hundred fifteen
UK: and is often included before the last part	115 is one hundred and fifteen
If there is nothing after hundred, stop there	900 is nine hundred

For 1,000–999,999, say the thousands group, then thousand, then the remaining part. If the remaining part is under 100, some speakers include and in British English, but it is optional in American English. When the last group begins with zeros, you still say the non-zero part normally.

Rule	Example
Pattern: thousands group + thousand + remainder	58,210 is fifty-eight thousand two hundred ten
If the remainder is 0, end after thousand	12,000 is twelve thousand
If the remainder is under 100, UK often uses and	3,045 is three thousand and forty-five
Do not say each zero; skip empty places	20,006 is twenty thousand six

For one million and higher, the same 3-digit grouping rule applies: say the million group, then million, then the next group, continuing down. Each group can be spoken as a normal number from 1 to 999. This repetition makes very large numbers predictable once you know the scale words.

Rule	Example
Say each non-zero 3-digit group with its scale word	4,501,020 is four million five hundred one thousand twenty
Keep the order: million before thousand before hundred	9,010,300 is nine million ten thousand three hundred
If a middle group is 000, skip that scale word	7,000,400 is seven million four hundred

In modern English, billion usually means one thousand million, which is 1,000,000,000. Historically, some British usage used billion for a million million, but this is rare today and can cause confusion in older texts. In international contexts, it is safest to confirm whether the short scale meaning is intended.

Region	Word	Regional Definition
US and modern UK	billion	1,000,000,000
older UK texts	billion	1,000,000,000,000

In standard American writing, commas separate 3-digit groups in large numbers. Many other places use spaces or periods instead of commas, so formatting can vary internationally. When reading aloud, you do not say comma; you use scale words like thousand and million to reflect the grouping.

Region	Word	Regional Definition
US writing	comma grouping	1,234,567
many EU formats	space grouping	1 234 567
some EU formats	period grouping	1.234.567

For decimals, English says point and then reads digits after the point one by one, even in large numbers. The whole number part is read using the normal large-number rules. In some regions, a comma is used as the decimal marker in writing, but spoken English still typically uses point.

Rule	Example
Say point for the decimal marker	2.5 is two point five
Read digits after point individually	3.141 is three point one four one
Read the whole number part normally first	12,000.08 is twelve thousand point zero eight

English often uses approximate words to simplify very large numbers in speech and writing. You can round to the nearest thousand, million, or billion and signal it with about, around, or roughly. You can also use expressions like a couple of and a few to keep the meaning informal and approximate.

Word/Phrase	Definition	Example
about	approximate, not exact	about two million
around	approximate, conversational	around 50,000
roughly	approximate, slightly formal	roughly 1.2 billion
a couple of	approximately two	a couple of thousand
a few	a small number, not exact	a few million

To communicate large numbers clearly, pause at scale words and keep a consistent grouping rhythm. If a number is important, repeat it using digits or by restating the groups. When listening, focus on the scale words first, because they define the size of the number.