Fractional part

• The fractional part (or decimal part) of non-negative real number $x$ is defined as: $\mathrm{frac}(x):=x-\lfloor x\rfloor$
  • also denoted by $\{x\}$, e.g., $\{3.14\}=0.14$
  • (the fractional part of logarithm result is also called the mantissa, e.g., in ${\log }_{10}(50)\approx 1.699$, the part $.699$ is the mantissa. in contrast, the integer part of logarithm result is called the characteristic)