Radix

In any standard positional numeral system, a number is conventionally written as (x)y with x as the string of digits and y as its base.

For base ten, the subscript is usually assumed and omitted (together with the enclosing parentheses), as it is the most common way to express value.

Root can be considered a synonym for base, in the arithmetical sense.

Generally, in a system with radix b (b > 1), a string of digits d1 ... dn denotes the number d1bn−1 + d2bn−2 + … + dnb0, where 0 ≤ di < b.

However, other positional systems are possible, for example, golden ratio base (whose radix is a non-integer algebraic number),[5] and negative base (whose radix is negative).