Are missed prayers to be calculated from the age of ten or from puberty? Is it permissible to make them up during times when prayer is prohibited? Is anything beyond the required amount considered supererogatory?

A prayer missed intentionally must be made up, though there is a difference of opinion on this. Prayer is not obligatory before puberty, so there is no making up for what was left before then. Maliki jurists permit making up two days' worth of prayers with each day, and there is no harm in adopting this view. It is permissible to make up missed prayers during times when prayer is ordinarily prohibited, according to the majority of scholars. The making up is done through an estimation, and anything beyond that is considered a supererogatory act.