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.

A number expressed in the scale of tens; specifically, and almost exclusively, used as synonymous with a decimal fraction.

Pertains primarily to decimal fractions. Decimal fractions are fractions with denominators of ten (10) or powers of ten (100,1000, etc). Example: 12.213 is 12 plus .213.213 is the same as 213/1000.213 is a decimal fraction

Decimals are numbers expressed in base-10 math. Decmials, when used as statistics, are representations with denominator some power of 10. Major League Baseball indicates batting average as a decimal quantity.