Program to understand the floating point arithmetic operation

#includea$=12\mathrm{.}4,b=3\mathrm{.}8=\%\mathrm{.}2fa+b=\%\mathrm{.}2$flna$-b=\%\mathrm{.}2\frac{f}{?}$

${?}^{\text{'}},a^{**}b\frac{a}{\frac{?}{?}}b=\%\mathrm{.}2fln,\frac{a}{b}=16\mathrm{.}20=8\mathrm{.}60=47\mathrm{.}12\frac{a}{b}=3\mathrm{.}26$