Numeral systems by culture  

HinduArabic numerals  
Eastern Arabic Indian family Khmer 
Mongolian Thai Western Arabic 
East Asian numerals  
Chinese Counting rods Japanese 
Korean Suzhou 
Alphabetic numerals  
Abjad Armenian Āryabhaṭa Cyrillic 
Ge'ez Greek (Ionian) Hebrew 
Other systems  
Attic Babylonian Brahmi Egyptian Etruscan Inuit 
Mayan Quipu Roman Urnfield 
List of numeral system topics  
Positional systems by base  
Decimal (10)  
1, 2, 3, 4, 5, 8, 12, 16, 20, 60 more…  
The base24 system is a numeral system with 24 as its base.
There are 24 hours in a day, so our time keeping system includes a base24 component. See also base 12.
Decimal Equivalent 10 twenty four 24 24 100 ? 24^2 = 576 1000 ? 24^3 = 13 824 10 000 ? 24^4 = 331 776 100 000 ? 24^5 = 7 972 624 1 000 000 ? 24^6 = 191 102 976
The digits used for numerals ten (10) to twenty three (23) may be the letters "A" through to "P" ("I" and "O" are skipped to prevent confusion with the digits 1 and 0 in some typefaces).
Quadrovigesimal fractions are usually either very simple
1/2 = 0.C 1/3 = 0.8 1/4 = 0.6 1/6 = 0.4 1/8 = 0.3 1/9 = 0.2G 1/C = 0.2 1/G = 0.1C 1/J = 0.18
or complicated
1/5 = 0.4K4K4K4K... recurring (easily rounded to 0.5 or 0.4K) 1/7 = 0.3A6LDH3A6... recurring 1/A = 0.29E9E9E9... recurring (rounded to 0.2A) 1/B = 0.248HAMKF6D248.. recurring (rounded to 0.24) 1/D = 0.1L795CN3GEJB1L7.. recurring (rounded to 0.1L) 1/P = 0.11111... recurring (rounded to 0.11) 1/11 = 0.0P0P0P... recurring (rounded to 0.0P) (1/(5*5))
As explained in recurring decimals, whenever a fraction is written in "decimal" notation, in any base, the fraction can be expressed exactly (terminates) if and only if all the prime factors of its denominator are also prime factors of the base. Thus, in base10 (= 2×5) system, fractions whose denominators are made up solely of multiples of 2 and 5 terminate: ¹⁄_{8} = ¹⁄_{(2*2*2)}, ¹⁄_{20} = ¹⁄_{(2×2×5)}, and ¹⁄_{500} (2²×5³) can be expressed exactly as 0.125, 0.05, and 0.002 respectively. ¹⁄_{3} and ¹⁄_{7}, however, recur (0.333... and 0.142857142857...). In the duodecimal (= 2×2×3) system, ¹⁄_{8} is exact; ¹⁄_{20} and ¹⁄_{500} recur because they include 5 as a factor; ¹⁄_{3} is exact; and ¹⁄_{7} recurs, just as it does in base 10.
In practical applications, the nuisance of recurring decimals is encountered less often when quadrovigesimal (or duodecimal) notation is used.
However when recurring fractions do occur in quadrovigesimal notation, they sometimes have a very short period when they are numbers containing one or two factors of five, as 5² = 25 is adjacent to 24. The other adjacent number, 23, is a prime number. So certain powers of five are palindromes in the quadrovigesimal notation:
5^{1} = 5 5^{2} = 11 5^{3} = 55 5^{4} = 121 5^{5} = 5A5 5^{6} = 1331 5^{7} = 5FF5 5^{8} = 14641
The multiples of decimal hundred are 44, 88, CC, GG, LL, 110, etc.
UmbuUngu, also known as Kakoli, is reported to have base24 numerals.^{[1]}^{[2]} Tokapu means 24, tokapu talu means 24×2 = 48, and tokapu tokapu means 24×24 = 576.
