Decimal

1. Of or pertaining to decimals; numbered or proceeding by tens; having a tenfold increase or decrease, each unit being ten times the unit next smaller; as, decimal notation; a decimal coinage.
   
Decimal arithmetic ,
the common arithmetic, in which numeration proceeds by tens.
Decimal fraction ,
a fraction in which the denominator is some power of 10, as 2/10, 25/100, and is usually not expressed, but is signified by a point placed at the left hand of the numerator, as .2, .25.
Decimal point ,
a dot or full stop at the left of a decimal fraction. The figures at the left of the point represent units or whole numbers, as 1.05.

1. A number expressed in the scale of tens; specifically, and almost exclusively, used as synonymous with a decimal fraction.
   
Circulating decimal, or Circulatory decimal ,
a decimal fraction in which the same figure, or set of figures, is constantly repeated; as, 0.354354354; -- called also recurring decimal, repeating decimal, and repetend.