Paying fidyah for the missed Salaahs and Fasts of the deceased
Q: We Sunni-hanafi, wish to pay as fidya for Qadha namaaz and roza for my mother and father, but I do not know how much they had qaza. I always found them Pious and humble, praying and careful about Namaaz and Rowza, except during last days of illness. What is the Islamic ruling for this? How can I calculate days and amount how to spend? Bearing expenses of a student heading towards hafiz e quran or Alim e deen, or donation for construction of Mosque considered as Sadaqa-e-jaria for my parents? What are other ways for this intention. Request for prayers for my parents to get best place in Jannat and Magfirat.