What must I do about the missed prayers and incomplete fasts in the past, given my current ignorance of their number?

The questioner must estimate the number of prayers and days they missed since puberty and make them up to the best of their ability, as these are debts upon them. We have explained what is required for someone who missed prayers and days of Ramadan without knowing their number in Fatwa No. 72777. There is a strong difference of opinion among scholars regarding the obligation to make up intentionally missed prayers, which can be reviewed in Fatwa No. 103454. They should also maintain obedience, increase in good deeds that wipe away sins, and draw closer to Allah through supererogatory acts.