Handling coherent states by undergraduates students may be a hard task, as they have to deal with Glauber's series $e^{-\frac {|\alpha|^2} {2}}\sum\limits_{n=0}^\infty\frac {\alpha^n} {\sqrt{n!}}\phi_n(x)$. We show here that the task can be greatly simplified by introduction of a novel compact formula for Glauber coherent states employed in [ Int. J. Mod. Phys. B {\bf 31} (2017) 175051]. This expression is obtained by solving the basic differential equation associated to coherent states $a|\alpha>=\alpha|\alpha>$.