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 to the left of the decimal separator (see also truncation). For a nonnegative decimal, it is the largest integer that is not greater than the decimal. The part from the decimal separator to the right is the "fractional part", which equals the difference between the numeral and its integer part. When the integral part of a numeral is zero, it may occur, typically in computing, that the integer part is not written (for example , instead of ). In normal writing, this is generally avoided because of the risk of confusion between the decimal mark and other punctuation. Decimal numerals