The approximation signal "≈" I use for decimal approximations with tilde "~" remaining a rougher approximation. But I question this. Ramanujan proved some of his collection for $1/pi$ and gave numerous information about his method in his paper along with his Notebooks. And how Ramanujan handled symbolic and numerical manipulation, https://travisujvfo.madmouseblog.com/16900851/the-por-qué-es-bueno-leer-el-tarot-diaries