Binary number converted to binary, whereupon the first converted piece is multiplied by 10 and added to the second converted piece, where "k" is the number of decimal digits in the second, least-significant piece before conversion. Binary may be converted to and from hexadecimal more easily. This is because the radix of the hexadecimal system (16) is a power of the radix of the binary system (2). More specifically, 16 = 2, so it takes four digits of binary to represent one digit of hexadecimal, as shown in the adjacent table. To convert a hexadecimal number into its binary equivalent, simply substitute
Combinatorial number system of a set "S" is a subset of "S" with "k" (distinct) elements. The main purpose of the combinatorial number system is to provide a representation, each by a single number, of all formula_1 possible "k"-combinations of a set "S" of "n" elements. Choosing, for any "n", } as such a set, it can be arranged that the representation of a given "k"-combination "C" is independent of the value of "n" (although "n" must of course be sufficiently large); in other words considering "C" as a subset of a larger set by increasing "n" will not change the number that