Decimal computer Decimal computer Decimal computers are computers which can represent numbers and addresses in decimal as well as providing instructions to operate on those numbers and addresses directly in decimal, without conversion to a pure binary representation. Some also had a variable wordlength, which enabled operations on numbers with a large number of digits. Early computers that were exclusively decimal include the ENIAC, IBM NORC, IBM 650, IBM 1620, IBM 7070. In these machines, the basic unit of data was the decimal digit, encoded in one of several schemes, including binary-coded decimal or BCD, bi-quinary, excess-3, and two-out-of-five code. Except for
Decimal representation procedure to formula_32 and denoting the resultant decimal expansion by formula_33. The decimal expansion of non-negative real number "x" will end in zeros (or in nines) if, and only if, "x" is a rational number whose denominator is of the form 25, where "m" and "n" are non-negative integers. Proof: If the decimal expansion of "x" will end in zeros, or formula_34 for some "n", then the denominator of "x" is of the form 10 = 25. Conversely, if the denominator of "x" is of the form 25, formula_35 for some "p". While "x" is of the form formula_36, formula_37