Check the picture below.
we can simplly check what's the volume before the ball, and check what's the volume after the ball is dropped, and get the difference.
[tex]\stackrel{\textit{volume before the ball}}{V=\pi r^2 h}\qquad \qquad \stackrel{\textit{volume after the ball}}{V_1=\pi r^2(h+4)}~\hfill \stackrel{\textit{their difference is simply}}{V_1-V} \\\\[-0.35em] ~\dotfill\\\\ \pi (5)^2(h+4)~~ - ~~\pi (5)^2h\implies 25\pi (h+4)~~ -~~25\pi h \\\\\\ ~~\begin{matrix} 25\pi h \\[-0.7em]\cline{1-1}\\[-5pt]\end{matrix}~~+100\pi ~~ - ~~~~\begin{matrix} 25\pi h \\[-0.7em]\cline{1-1}\\[-5pt]\end{matrix}~~\implies 100\pi ~~\approx~~314.16[/tex]
