The common names for negative-base positional numeral systems are formed by prefixing nega- to the name of the corresponding positive-base system; for example, negadecimal (base −10) corresponds to decimal (base 10), negabinary (base −2) to binary (base 2), negaternary (base −3) to ternary (base 3), and negaquaternary (base −4) to quaternary (base 4). ex) 383.1234₍₁₀₎=3*10^2+8*10^1+3*10^0 / +1*10^-1+2*10^-2+3*10^-3+4*10^-4 383.1234₍₁₀₎=600.701255₍₋₈₎=6*(-8)^2+7*(-8)^-1+1*(-8)^-3+2*(-8)^-4+5*(-8)^-5+5*(-8)^-6=383.1234016418457 383.0234₍₁₀₎=617.024027₍₋₈₎=6*(-8)^2+1*(-8)^1+7+2*(-8)^-2+4*(-8)^-3+2*(-8)^-5+7*(-8)^-6=383.0234031677246 en.wikipedia.org/wiki/Negative_base