Thai numerals
Thai numerals are a set of numerals traditionally used in Thailand, although the Arabic numerals are more common due to extensive westernization of Thailand in the modern Rattanakosin period. Thai numerals follow the Hindu–Arabic numeral system commonly used in the rest of the world. In the Thai language, numerals often follow the modified noun and precede a measure word, although variations to this pattern occur.
Usage
The Thai language lacks grammatical number. A count is usually expressed in the form of an uninflected noun followed by a number and a classifier. "Five teachers" is expressed as "teacher five person" khru ha khon Khon "person" is a type of referent noun that is also used as the Thai part of speech called in English a linguistic classifier, or measure word. In Thai, counting is kannap ; the classifier, laksananam Variations to this pattern do occur, and there really is no hierarchy among Thai classifiers.A partial list of Thai words that also classify nouns can be found in Wiktionary category: Thai classifiers
Main numbers
Zero to ten
Thai sūn is written as oval 0 (number) when using Arabic numerals, but a small circle ๐ when using traditional numerals, and also means centre in other contexts. It is from Sanskrit śūnya, as are the alternate names for numbers one to four given below; but not the counting 1 (number).Thai names for N +1 and the regular digits 2 through 9 as shown in the table, below, resemble those in Chinese varieties as spoken in Southern China, the homeland of the overseas Chinese living in South East Asia. In fact, the etymology of Thai numerals 2, 3, 4, 6, 7, 8, 9, and 10 is Middle Chinese, while the etymology of Thai numeral 5 is Old Chinese, as illustrated in the table below.
Numerical digit characters, however, are almost identical to Khmer numerals. Thai and Lao words for numerals are almost identical, however, the numerical digits vary somewhat in shape. Shown above is a comparison between three languages using Cantonese and Minnan characters and pronunciations. Shown below is a comparison between three languages using Khmer numerals: Thai, Khmer, and Lao. The Thai transliteration uses the Royal Thai General System of Transcription.
Ten to a million
Sanskrit lakh designates the place value of a digit, which are named for the powers of ten: the unit's place is lak nuai ; ten's place, lak sip ; hundred's place, lak roi, and so forth. The number one following any multiple of sip becomes et. The number ten is the same as Literary Hokkien 十. Numbers from twenty to twenty nine begin with yi sip ; Hokkien: 二十 ; Teochew: 二十 ). Names of the lak sip for 30 to 90, and for the lak of 100, 1000, 10,000, 100,000 and million, are almost identical to those of the like Khmer numerals.For the numbers twenty-one through twenty-nine, the part signifying twenty: yi sip, may be colloquially shortened to yip. See the alternate numbers section below.
The hundreds are formed by combining roi with the tens and ones values. For example, two hundred and thirty-two is song roi sam sip song. The words roi, phan, muen, and saen should occur with a preceding numeral, so two hundred ten, for example, is song roi sip, and one hundred is either roi or nueng roi. Nueng never precedes sip, so song roi nueng sip is incorrect. Native speakers will sometimes use roi nueng with different tones on nueng to distinguish one hundred from one hundred and one. However, such distinction is often not made, and ambiguity may follow. To resolve this problem, if the number 101 is intended, one should say roi et.
Numbers above a million
Numbers above a million are constructed by prefixing lan with a multiplier. For example, ten million is sip lan, and a trillion is lan lan.Decimal and fractional numbers
Colloquially, decimal numbers are formed by saying chut where the decimal separator is located. For example, 1.01 is nueng chut sun nueng.Fractional numbers are formed by placing nai between the numerator and denominator or using x suan y to clearly indicate. For example, is nueng nai sam or nueng suan sam. The word set can be omitted.
The word khrueng is used for "half". It precedes the measure word if used alone, but it follows the measure word when used with another number. For example, kradat khrueng phaen means "half sheet of paper", but kradat nueng phaen khrueng means "one and a half sheets of paper".
Negative numbers
Negative numbers are formed by placing lop in front of the number. For example, −11 is lop sip et.Ordinal numbers
s are formed by placing thi in front of the number. They are not considered a special class of numbers, since the numeral still follows a modified noun, which is thi in this case.| Thai | RTGS | IPA | meaning |
| ที่หนึ่ง | thi nueng | first | |
| ที่สอง | thi song | second | |
| ที่สาม | thi sam | third | |
| ที่สี่ | thi si | fourth | |
| ที่# | thi # | #st, #nd, #rd, #th |