Cardinal and Ordinal Numbers

 

1. The numbers in English

1.1. Cardinal numbers

Cardinal numbers say how many people or things there are.

Examples:

• There are five books on the desk.
• Ron is ten years old.

1.1.1. Numbers bigger than 20

Use a hyphen between compound numbers.

Number	Word
21	twenty-one
55	fifty-five
99	ninety-nine

1.1.2. Numbers bigger than 100

Use a hyphen between compound numbers and the word and.

Use either the definite article a or one for 100.

Number	Word
121	a/one hundred and twenty-one
356	three hundred and fifty-six
999	nine hundred and ninety-nine

In American English and is mostly not used.

1.1.3.Numbers bigger than 1,000

Use a hyphen between compound numbers and the word and.

Use either the definite article a or one for 1,000.

Separate three digits with a comma (,) → 50,000.

Number	Word
1,121	a/one thousand and one hundred and twenty-one
2,356	two thousand and three hundred and fifty-six
9,999	nine thousand and nine hundred and ninety-nine
305,234	three hundred and five thousand and two hundred and thirty-four

In American English and is mostly not used.

1.1.4. The number 0

There are different words for the number 0.

Word	Explanation	Example
oh	single digits (telephone numbers, codes)	67890 six - seven - eight - nine - oh
zero	measurements (temperature)	-5 °C five degrees Celsius below zero
nought	figure 0 in British English*	5 - 5 = 0 Five minus five leaves nought.
nil	results in sport	The match ended 2 - 0. The match ended two - nil.
love	tennis	40 - 0 forty - love

* In American English zero is used.

1.1.5. Year

see: The date and the year in English

1.2. Ordinal numbers

Add th to the cardinal number to form the ordinal number: six → sixth

Add the last two letters of the written word to the figure. → 4th

Numbers in words: The ordinal numbers 1st → first, 2nd → second and 3rd → third are irregular. Be careful with the spelling of the words for 5th, 8th, 9th, 12th and the words ending in -y.

Cardinal numbers		Ordinal numbers
1	one	1st	first
2	two	2nd	second
3	three	3rd	third
5	five	5th	fifth
8	eight	8th	eighth
9	nine	9th	ninth
12	twelve	12th	twelfth
20	twenty	20th	twentieth

 

Ordinal numbers
21st	twenty-first
22nd	twenty-second
23rd	twenty-third
24th	twenty-fourth
25th	twenty-fifth
26th	twenty-sixth
27th	twenty-seventh
28th	twenty-eighth
29th	twenty-ninth
30th	thirtieth
31st	thirty-first

1.3. Fractions and decimals

1.3.1. Fractions

Use the ordinal number for the denominator:

• 1/3 → one third
• 2 3/5 → two and three fifths

Exceptions:

• 1/2 → one half
• 1/4 → one quarter

1.3.2. Decimals

Use the cardinal number for decimals:

• 3.8 → three point eight
• 4.25 → four point two five

1.4. Roman numbers

Roman numbers are seldom used. They are used for the names of kings and queens. Use the ordinal number:

• Elisabeth II → Elisabeth the Second
• Louis XIV → Louis the Fourteenth

2. The numbers in a table

Cardinal numbers		Ordinal numbers
0	oh, zero, nil, love, nought	---
1	one	1st	first
2	two	2nd	second
3	three	3rd	third
4	four	4th	fourth
5	five	5th	fifth
6	six	6th	sixth
7	seven	7th	seventh
8	eight	8th	eighth
9	nine	9th	ninth
10	ten	10th	tenth
11	eleven	11th	eleventh
12	twelve	12th	twelfth
13	thirteen	13th	thirteenth
14	fourteen	14th	fourteenth
15	fifteen	15th	fifteenth
16	sixteen	16th	sixteenth
17	seventeen	17th	seventeenth
18	eighteen	18th	eighteenth
19	nineteen	19th	nineteenth
20	twenty	20th	twentieth
21	twenty-one	21st	twenty-first
22	twenty-two	22nd	twenty-second
23	twenty-three	23rd	twenty-third
24	twenty-four	24th	twenty-fourth
25	twenty-five	25th	twenty-fifth
26	twenty-six	26th	twenty-sixth
27	twenty-seven	27th	twenty-seventh
28	twenty-eight	28th	twenty-eighth
29	twenty-nine	29th	twenty-ninth
30	thirty	30th	thirtieth
31	thirty-one	31st	thirty-first
40	forty
50	fifty
60	sixty
70	seventy
80	eighty
90	ninety
100	a/one hundred
1,000	a/one thousand
10,000	ten thousand
100,000	a/one hundred thousand
1,000,000	a/one million
1,000,000,000	a/one billion

---

Source:https://www.englisch-hilfen.de/en/grammar/zahlen.htm