Ramanujan pie Infinity series 1/π

\frac{1}{\pi} = \frac{2\sqrt{2}}{9801} \sum_{k=0}^{\infty} \frac{(4k)!(1103 + 26390k)}{(k!)^4 396^{4k}}

How this is derived I am in seventh class but have curiosity in pure math and quantum physics I don't understand this please could any one explain the derivation of this and my name Is aashish Das form India