Output each floating$-$point value with two digits after the decimal point, which can be achieved as follows:

print$($f$\text{'}\{$your$\_$value:$\mathrm{.}2$f$\}\text{'})$

Ex: If the input is:

$100$

the output is:

After $6$ hours: $50\mathrm{.}00$ mg

After $12$ hours: $25\mathrm{.}00$ mg

After $24$ hours: $6\mathrm{.}25$ mg