Numbers
If math describes how the world works, numbers are the alphabet that makes math possible. In this lesson, we will discover all about them.
What are Numbers?
Numbers are mathematical objects, we use them to express quantity. We use numbers to count, label, and measure. We can see the use of numbers everywhere, we use them to tell dates, phone numbers, and so on.
Types of Numbers in English Grammar
There are two main groups of numbers in English grammar:
Cardinal Numbers
Cardinal numbers (also called cardinals) are used to show a general number of people, animals, or things such as two, six, twelve, five hundred. They show how many of those things or people there are.
Placement
Cardinal numbers are commonly used as determiners. In other words, they are typically used before nouns.
I love my pets. I have
When used as a determiner, they can also take predeterminers such as articles or possessive determiners before them. For example:
My
We can use cardinal numbers with the structure:
cardinal numbers + of + determiners
Tip!
Cardinal numbers can also be used as nouns:
People came to the theater in
Numbers Bigger Than Twenty
If you want to write numbers bigger than twenty, you should use a hyphen between parts of the compound number. In other words, hyphenate all compound numbers from twentyone through ninetynine. For example:
Numbers Bigger Than 100
With numbers bigger than 100, you should use a hyphen between compound numbers after the word 'and.'
For 100, we can either use the definite article 'a' or use 'one.'
a/one hundred and
eight hundred and
In American English, people normally do not use the word 'and':
three hundred fiftysix
Numbers Bigger Than 1,000
For numbers bigger than 1,000, put a hyphen between compound numbers and use the word 'and'. You can
use either the indefinite article 'a' or 'one' for 1,000.
Remember to use a comma to separate three digits → 80,000.
a/one thousand (and) one hundred (and) twentyone
In American English and is mostly not used.
three hundred (and) five thousand (and) two hundred (and) thirtyfour
Number 0
The number 0 has many names:
 in telephone numbers, codes, etc. →
oh  in measurements and temperature →
zero  in British English →
nought  in sports commentary →
nil  in tennis →
love
What Are Ordinal Numbers?
Ordinal numbers are used to show the position of something in a list or in a row, that's why we call them ordinal. Here are a few examples:
This is the
She is the
How to Make Ordinal Numbers?
Most of the numbers get th at the end to change to an ordinal number except the first three numbers. Check out the table below:

twentie 

thirtie 

fortie 
four 
fiftie 
fif 
sixtie 
six 
seventie 
seven 
eightie 
eigh 
ninetie 
nin 
hundred 
ten 
thousand 
Now let us take a look at the numbers that have two parts such as twentyone:
twentyfirst (21st)  one hundred and thirtyfirst (131th) 
twentysecond (22nd)  two hundred and fortyfifth (245th) 
twentythird (23rd)  three hundred and fiftyseventh (357th) 
When Do We Use Ordinal Numbers?
Ordinal numbers are used in many different cases as follows:
 fractions
 Roman numerals
 telling the dates and talking baout centuries
Fractions
A fraction is a particular form of writing numbers. Fractions are used to express a part of a whole or a collection. Here are some examples:
fraction
Roman Numerals
The letters: I, V, X, L, C, D, and M in the Latin alphabet were used to express numbers in ancient Greece, nowadays we still use them in some cases, Let's is an example:
Alice III → Alice the
Roman number
Telling the Dates and Century
My birthday is on June the
telling the dates
The castle was built in the
talking about centuries
How to Write Ordinal Numbers
When we want to write the ordinal numbers in the number form you should use the last two letters in a smaller form after the cardinal number, for example:
 first = 1st
 second = 2nd
 third = 3rd
 fourth = 4th
Talking about Money & Prices
Each country has its own system of money, such as the Dollar in the USA, the Pound in the UK, and the Euro in European countries. There are different ways to say the prices, Let's go through the common ones:
One, Two, Three Digit Prices
$4.20 → Fourtwenty
just say the numbers
$4.20 → Four dollars (and) twenty
saying "and" is more common in british english, and americans mostly don't say it.
$4.20 → Four dollars and twenty cents
we have said the units and the numbers and this is the formal way
$580
if the price is an exact number of pounds, euros or dollars we should say it completely.
£100→ a hundred pounds
the price beginning with "one" we could use "a" instead of one.
Four Digit Prices
Mostly the method to read four digit numbers is the same as we have explained above, but there are some exceptions as well.
$1250 → a thousand two hundred fifty
$5260 → five thousand two hundred sixty
$
we can also say a thousand five hundred