Decimal numbers that may be expressed as a fraction, the denominator of which is a power of ten. For example, the numerals formula_5 represent the fractions , , . More generally, a decimal with digits after the separator represents the fraction with denominator , whose numerator is the integer obtained by removing the separator. Expressed as a fully reduced fraction, the decimal numbers are those, whose denominator is a product of a power of 2 by a power of 5. Thus the smallest denominators of decimal numbers are The "integer part", or "integral part" of a decimal is the integer written
Decimal but may be a comma "" in other countries (mainly in Europe). For representing a nonnegative number, a decimal consists of It is generally assumed that, if , the first digit is not zero, but, in some circumstances, it may be useful to have one or more 0's on the left. This does not change the value represented by the decimal. For example, . Similarly, if , it may be removed, and conversely, trailing zeros may be added without changing the represented number. For example, and . sometimes, the unnecessary zeros are used for indicating the accuracy of a measurement.