Hindu–Arabic numeral system system is based upon ten (originally nine) different glyphs. The symbols (glyphs) used to represent the system are in principle independent of the system itself. The glyphs in actual use are descended from Brahmi numerals and have split into various typographical variants since the Middle Ages. These symbol sets can be divided into three main families: Western Arabic numerals used in the Greater Maghreb and in Europe, Eastern Arabic numerals (also called "Indic numerals") used in the Middle East, and the Indian numerals used in South Asia. The Hindu-Arabic numerals were invented by mathematicians in India. Perso-Arabic mathematicians called them
Japanese numerals facing each other) – so six has the index finger against the palm, and so forth. To display ten, one presents both hands open and palm outwards. Since the adoption of Arabic numerals, numbers have become written in Arabic numerals more and more often. Counters and ordinal numbers are typically written in Arabic numbers, such as 3人 (three people), 7月 (July, "seventh-month"), 20歳 (age 20), etc., although 三人、七月、and 二十歳 are also acceptable to write (albeit less common). However, numbers that are part of lexemes are typically written in kanji. For example, the term "yaoya" 八百屋 (tr.: vegetable stand / grocer)