Number Name Rules
Standard English Language Rules for Number Names

Cardinal Number Symbol	Cardinal Number Name	Ordinal Number Symbol	Ordinal Number Name
0	zero
1	one	1^st	first
2	two	2^nd or 2^d	second
3	three	3^rd or 3^d	third
4	four	4^th	fourth
5	five	5^th	fifth
6	six	6^th	sixth
7	seven	7^th	seventh
8	eight	8^th	eighth
9	nine	9^th	ninth
10	ten	10^th	tenth
11	eleven	11^th	eleventh
12	twelve	12^th	twelfth
13	thirteen	13^th	thirteenth
14	fourteen	14^th	fourteenth
15	fifteen	15^th	fifteenth
16	sixteen	16^th	sixteenth
17	seventeen	17^th	seventeenth
18	eighteen	18^th	eighteenth
19	nineteen	19^th	nineteenth
20	twenty	20^th	twentieth
21	twenty-one	21^st	twenty-first
22	twenty-two	22^nd or 22^d	twenty-second
23	twenty-three, etc.	23^rd or 23^d	twenty-third, etc.
30	thirty	30^th	thirtieth
40	forty	40^th	fortieth
50	fifty	50^th	fiftieth
60	sixty	60^th	sixtieth
70	seventy	70^th	seventieth
80	eighty	80^th	eightieth
90	ninety	90^th	ninetieth
100	one hundred	100^th	one hundredth
101	one hundred one	101^st	one hundred first
102	one hundred two	102^nd or 102^d	one hundred second
103	one hundred three, etc.	103^rd or 103^d	one hundred third, etc.
1,000	one thousand	1,000^th	one thousandth
1,001	one thousand one	1,001^st	one thousand first
1,002	one thousand two	1,002^nd or 1,002^d	one thousand second
1,003	one thousand three, etc.	1,003^rd or 1,003^d	one thousand third, etc.
10,000	ten thousand	10,000^th	ten thousandth
100,000	one hundred thousand	100,000^th	one hundred thousandth
1,000,000	one million	1,000,000^th	one millionth
1,000,001	one million one	1,000,001^st	one million first
1,000,002	one million two	1,000,002^nd or 1,000,002^d	one million second
1,000,003	one million three, etc.	1,000,003^rd or 1,000,003^d	one million third, etc.
10,000,000	ten million	10,000,000^th	ten millionth
100,000,000	one hundred million	100,000,000^th	one hundred millionth
123,456,789	one hundred twenty-three million, four hundred fifty-six thousand, seven hundred eighty-nine	123,456,789^th	one hundred twenty-three million, four hundred fifty-six thousand, seven hundred eighty-ninth
See Number Names for the standard English language names for the integers one through ten thousand (1 through 10,000).

Cardinal Number Names

1. The English Language names of the cardinal numbers from zero (0) through nineteen (19) are unique.
2a. The names of the cardinal numbers from twenty (20) through ninety-nine (99) that are integer multiples of ten (10) are also unique.
2b. The names of the cardinal numbers from twenty (20) through ninety-nine (99) that are not integer multiples of ten (10) are formed by taking the name of the multiple of ten (10) cardinal number and adding a hyphen and the name of the units (1) digit cardinal number.
3. The names of the cardinal numbers from one hundred (100) through nine hundred ninety-nine (999) are formed by taking the name of the hundreds (100) digit cardinal number, adding the word "hundred", and, if the number is not a integer multiple of one hundred (100), adding the name of the cardinal number that is the residue of the number modulus one hundred (100).
4. The names of the cardinal numbers from one thousand (1,000) through nine hundred ninety-nine thousand nine hundred ninety-nine (999,999) are formed by taking the name of the multiple of one thousand (1,000) cardinal number, adding the word "thousand", and, if the number is not a integer multiple of one thousand (1,000), adding the name of the cardinal number that is the residue of the number modulus one thousand (1,000). See Number Names for the standard English language names for the cardinal numbers from zero through ten thousand (0 through 10,000).
5. The names of the cardinal numbers from one million (1,000,000) through nine hundred ninety-nine million nine hundred ninety-nine thousand nine hundred ninety-nine (999,999,999) are formed by taking the name of the multiple of one million (1,000,000) cardinal number, adding the word "million", and, if the number is not a integer multiple of one million (1,000,000), adding the name of the cardinal number that is the residue of the number modulus one million (1,000,000).
6. See the Integer Powers of One Thousand for the English Language names of larger cardinal numbers.
Example: one hundred twenty-three million, four hundred fifty-six thousand, seven hundred eighty-nine (123,456,789)

Ordinal Number Names

1. There is no ordinal number that corresponds with the cardinal number zero (0), although zero (0) is often used to denote a point of origin.
2. The English Language names of the ordinal numbers from first (1^st) through nineteenth (19^th) are unique.
3a. The names of the ordinal numbers from twentieth (20^th) through ninety-ninth (99^th) that are integer multiples of ten (10) are formed by taking the name of the corresponding cardinal number and replacing the suffix letters "-ty" with "-tieth".
3b. The names of the ordinal numbers from twentieth (20^th) through ninety-ninth (99^th) that are not integer multiples of ten (10) are formed by taking the name of the corresponding multiple of ten (10) cardinal number and adding a hyphen and the name of units (1) digit ordinal number.
4a. The names of the ordinal numbers that are integer multiples of one hundred (100) are formed by taking the name of the corresponding cardinal number and adding the suffix letters "-th".
4b. The names of the ordinal numbers greater than one hundredth (100^th) that are not integer multiples of one hundred (100) are formed by taking the name of the corresponding cardinal number and replacing the name of the cardinal number residue modulus one hundred (100) with the name of the corresponding ordinal number.
See Number Names for the standard English language names for the ordinal numbers from first through ten thousandth (1st through 10,000th).
Example: one hundred twenty-three million, four hundred fifty-six thousand, seven hundred eighty-ninth (123,456,789^th)

Rational Fraction Names

1. The English Language names of rational fractions with a denominator of two (2) are formed by taking the name of cardinal number numerator and adding the word "half" if the numerator is one (1) or "halves" if not.
2. The names of rational fractions with a denominator that is not two (2) are formed by taking the name of the cardinal number numerator, adding the name of the denominator expressed as an ordinal number with hyphens replacing any spaces in the name, and adding the suffix letter "-s" if the numerator is not one (1). The word "quarter" may be used instead of "fourth" for rational fractions with a denominator of four (4).
Example: three hundred fifty-five one-hundred-thirteenths (355/113)

Mixed Number Names

1. The English Language names of mixed numbers are formed by taking the name of the integer portion and adding the word "and" and the name of the rational fraction portion.
Example: one and one half (1½)

Decimal Fraction Names

1. The English Language name of a decimal fraction or mixed number is the same as corresponding rational fraction or mixed number.
2. A decimal mixed number may be verbally pronounced as the integer name, plus the word "point," plus the fractional portion pronounced as individual digits.
3. See the Integer Powers of 1000 for the English Language names for smaller decimal fractions.
Example: one and five tenths (1.5) also pronounced as "one point five"

Negative Number Names

1. The negation of zero (0) is also zero (0).
2. The English Language names of negative numbers are formed by taking the word "minus" or "negative" and adding the name of the corresponding positive number.
Example: minus forty (-40)

Dictionary of Number Words
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