Decimal and, only the best mathematicians were able to multiply or divide large numbers. These difficulties were completely solved with the introduction of the Hindu–Arabic numeral system for representing integers. This system has been extended to represent some non-integer numbers, called "decimal fractions" or "decimal numbers" for forming the "decimal numeral system". For writing numbers, the decimal system uses ten decimal digits, a decimal mark, and, for negative numbers, a minus sign "−". The decimal digits are 0, 1, 2, 3, 4, 5, 6, 7, 8, 9; the decimal separator is the dot "" in many countries (including English speaking ones),
Decimal separator an Arabic decimal separator () (in hex U+066B) in Unicode. An Arabic thousands separator () also exists. In Persian, the decimal separator is called "momayyez", which is written like a forward slash—there is a small difference between the "upside-down (Persian) comma" character used in sentences and the "Latin" comma () (in hex U+066B) used to separate sequences of three digits. To separate sequences of three digits, a Latin comma or blank space may be used; however this is not a standard. In English Braille, the decimal point, , is distinct from both the comma, , and the full stop, .