The decimal fractions are those in which the proportion in which relate van 10 in 10 of one to another or that have a constant proportionality. In fractions not decimal ratios are not maintained 10 in 10 but differ according to a few different conversions, are not constant. Fractions in the English system. For example a container or drum has 55 gallon, one gallon has 8 pints. Then a pint is one-eighth ( 1/8 ) gallon and a gallon is a cincuentaycincoavo ( 1/55 ) of a container. Used for keys in inches and fractions of inches.
decimal fraction = to make a fraction decimal it is necessary that the numerator is 10 or a power of 10, i.e., must be the number below the fraction 10,100,1000,etc. Example = 66/100 = 0, 66.