We use different words to describe numbers depending on how many digits (numbers) they contain. We can also refer to the number of digits for simple generalisations. For example, 10,000 is five digits, so we refer to it as in the tens of thousands, but we may also call it a five figure number.
These are some of the ways we can describe numbers. Individual numbers will be called by their name, for instance 4 is four, 13,425 is thirteen thousand four hundred and 25. But they can also be grouped or generalised in a variety of ways. For instance 4 is also a single figure (or digit) number, and 13,425 is in the tens of thousands. The following table shows how we can describe some groups of numbers as they increase in size:
Name 

1319 
teen 
10 
ten 
100 
hundred 
1000 
thousand 
10,000 
ten thousand 
100,000 
hundred thousand 
1,000,000 
million 
1,000,000,000 
billion 
1,000,000,000,000 
trillion 
In the past, there was a distinction between the American billion (1,000,000,000) and the British or European billion (1,000,000,000,000 – now the trillion), but in modern use the vast majority of the English speaking world has adopted the American version.
Saying a large number
We say large numbers by listing the numbers in order of size, biggest first. When reading a single number, all the number labels should be singular, for example 10,400 is ten thousand four hundred and not ten thousands four hundreds.
We describe three digit numbers in hundreds, then tens. Generally, in British English we usually connect large numbers with double or single digit figures with and, but in American English and is not used. Note that hundreds, thousands and millions are not connected to each other with and, though.
For example:
 345 is three hundred and fortyfive (three hundred forty five in American).
 59,321 is fifty nine thousand, three hundred and twenty one. (not fifty nine thousand and three hundred…)
You can then describe large numbers with a series of different figures, grouping numbers in hundreds and tens, starting with the biggest number. So we describe hundreds/tens of millions, then thousands, then hundreds:
 1,345,612 = one million, three hundred and forty five thousand, six hundred and twelve
 153,200 = one hundred and fifty three thousand, two hundred
In the…
When we want to say where a number generally lies, in the above groups, we can say it is in the… For example, 14 is in the teens, 325 is in the hundreds. For tens and hundreds of larger numbers (thousands, millions), we say in the tens (or hundreds) of… So: hundreds of thousands and tens of millions.
Hundreds and thousands
Often it is easier to describe four figure numbers in hundreds instead of thousands. This is perfectly acceptable. For example, 1500 might be described as fifteen hundred, instead of one thousand five hundred (or one and a half thousand), because it is simpler to say.
Numbers as adjectives
All of these numbers can be referred to by the number of figures they contain, with plurals, for instance a number is in single figures (3), double figures (20) or quadruple figures (1,000). However, when we use the figure size of the number to describe a noun (such as a salary, price or to refer to a number itself) we simply use number + figure + noun. For example, a sixfigure salary, a fourfigure discount.
Alternative names for number groups
There are many informal alternative names for groups of numbers that can be used to simplify names. Beware you may not always be understood using these.
singular 
example plural 

12 
dozen 
24 = 2 dozen 
20 
score 
80 = 4 score 
100 
century 
300 = centuries 
1,000 
grand, k 
Naming large numbers exercise
Practise reading these numbers out loud:
 4,567
 367
 98,745
 120,005
 5,000
 34,230
 873,120
 10,043
 7,340,200
 54,500
 24
 4,567,090
 67,000
 92,000,031
 1,000,010,000,023
Suggested Answers
 4,567 – four thousand, five hundred and sixtyseven
 342 – three hundred and fortytwo
 98,745 – ninetyeight thousand, seven hundred and fortyfive
 120,005 – one hundred and twenty thousand and five
 5,000 – five thousand, or five k, g or grand
 34,230 – thirty four thousand, two hundred and thirty
 873,120 – eight hundred and seventy three thousand, one hundred and twenty
 10,043 – ten thousand and forty three
 7,340,200 – seven million, three hundred and forty thousand, two hundred
 5,500 – five thousand, five hundred or fiftyfive hundred
 24 – two dozen
 4,567,090 – four million, five hundred and sixty seven thousand and ninety
 67,000 – sixty seven thousand, sixty seven k, grand or g
 92,000,031 – ninety two million and thirty one
 1,000,010,000,023 – one trillion, ten million and twenty three
Thanks.
165,200,000km’2 one hundered sixty five thousand two million .is that true please
Hi Raniya – the other way around, one hundred sixty five million (the larger number), two hundred thousand.
Very helpful, thanks!!
You’re welcome!
342 three hundred and forty two. Can I just say three hundred forty two instead?
Hi Mary Ann – yes you can, in spoken English.
Helped me a lot!!!
You put 1,000,000,000,000 as quadrillion when it is actually one trillion!
Hi Evan, thanks for spotting that – not sure how that slipped through, but I’ve updated it now!
Thanks a lot. I was struggling with big numbers which had zero as the 3rd / 2nd last digit of the number like 345 004. I was like three hundred and forty five thousand four. Having read this lesson, it’s now three hundred and forty five thousand and four.
You’re welcome, I’m glad it’s helped!