Cardinal and Ordinal Numbers


There are two main types of numbers:
  1. Cardinal Numbers - 1 (one), 2 (two) etc. (Used mainly for counting)
  2. Ordinal Numbers - 1st (first), 2nd (second) etc. (Used mainly for putting things in a sequence)

Cardinal Numbers

Cardinal numbers are normally used when you:
  • Count things: I have two brothers. There are thirty-one days in January.
  • Give your age: I am thirty-three years old. My sister is twenty-seven years old.
  • Give your telephone number: Our phone number is two-six-three, three-eight-four-seven. (481-2240)
  • Give years: She was born in nineteen seventy-five (1975). America was discovered in fourteen ninety-two. Notice how we divide the year into two parts. This is the form for year up to 1999. For the year 2000 and on, we say two thousand (2000), two thousand and one (2001), two thousand and two (2002) etc.

Ordinal Numbers

You can normally create Ordinal numbers by adding -TH to the end of a Cardinal Number. Ordinal numbers are normally used when you:
  • Give a date: My birthday is on the 27th of January. (Twenty-seventh of January)
  • Put things in a sequence or order: Liverpool came second in the football league last year.
  • Give the floor of a building: His office is on the tenth floor.
  • Have birthdays: He had a huge party for his twenty-first birthday.
Cardinal Numbers
1 - one
2 - two
3 - three
4 - four
5 - five6 - six
7 - seven
8 - eight
9 - nine
10 - ten
11 - eleven
12 - twelve
13 - thirteen
14 - fourteen
15 - fifteen
16 - sixteen
17 - seventeen
18 - eighteen
19 - nineteen
20 - twenty
21 - twenty-one
22 - twenty-two
23 - twenty-three
30 - thirty
40 - forty
50 - fifty
60 - sixty
70 - seventy
80 - eighty
90 - ninety
100 - one hundred
*101 - one hundred and one
200 - two hundred
300 - three hundred
1000 - one thousand
1,000,000 - one million
10,000,000 - ten million

Instead of saying One Hundred, you can say A hundred.
e.g. (127) one hundred and twenty-seven OR (127) a hundred and twenty-seven.

The same rule applies for one thousand (a thousand) and one million (a million)
Notice that you need to use a hyphen (-) when you write the numbers between 21 and 99.

With long numbers, we usually divide them into groups of three which are divided by a comma. e.g. 5000000 (5 million) is normally written as 5,000,000

Ordinal Numbers

1st - first
2nd - second
3rd - third
4th - four
5th - fifth
6th - sixth
7th - seventh
8th - eighth
9th - ninth
10th - tenth
11th - eleventh
12th - twelfth
13th - thirteenth
14th - fourteenth
15th - fifteenth
16th - sixteenth
17th - seventeenth
18th - eighteenth
19th - nineteenth
20th - twentieth
21th - twenty-first
22th - twenty-second
23rd - twenty-third
30th - thirtieth
40th - fortieth
50th - fifieth
60th - sixtieth
70th - seventieth
80th - eightieth
90th - ninetieth
100th - hundreth
101th - hundred and first
200th - two hundredth
300th - three hundredth
1,000th - thousandth
1,000,000th - ten millionth

The Number 0 We normally say 'zero' for the number '0'.
BUT when we give our telephone number, we often say O like the name of the letter O : /oÊŠ/
e.g. 505-1023 = five-O-five, one-O-two-three

Fractions and Decimals

We use ordinal numbers (at the end position) to talk about fractions.

1/2 - a half
1/3 - a third
2/3 - two thirds
1/4 - a quarter (a fourth)
3/4 - three quarters (three fourths)
1/5 - a fifth2/5 - two fifths
1/6 - a sixth
5/6 - five sixths
1/7 - a seventh
1/8 - an eighth
1/10 - a tenth
7/10 - seven tenths
1/20 - a twentieth
47/100 - forty-seven hundredths
1/100 - a hundredth
1/1,000 - a thousandth

Notice that for 1/4, you can say a quarter OR a fourth.

IF we have a whole number with a fraction, we use the word AND between the two parts.
e.g. 2 3/5 = two and a three-fifths

For parts of whole numbers, we use a decimal point (and NOT a comma).
e.g. 2 1/2 (two and a half) = 2.5 (two point five)

If there is more than one number after the decimal point, we say each number individually.
e.g. 3,456.789 = three thousand, four hundred and fifty-six point seven eight nine.

The exception to this rule is when we are talking about dollars and cents (or pound and pence) e.g. $21.95 = twenty-one dollars, ninety-five (cents).
Saying the word cents at the end is optional

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