One who prays in a direction other than the qiblah and does not know the number of prayers

Question:
I teach in the evening and I pray the 'Asr prayer at the school, and the qiblah was wrong. I do not know now how many prayers I have prayed in this direction, so please issue a ruling for us, may Allah reward you.

Answer:
If the qiblah was wrong in the sense that you did not face the qiblah or the direction in which the qiblah is, but rather you were turned away from the qiblah with your back or your side, then the prayer is invalid because it lacks one of the conditions for the validity of the prayer, which is facing the qiblah. However, if the deviation is slight and does not take you out of the direction in which the qiblah is, then the prayer is valid, and praise be to Allah. As for the first case, where one deviated completely, he must repeat the prayer because it is not valid. If he does not know the number of prayers, he should estimate it and act on the most cautious estimate. As for the one who prayed in the town in a direction other than the qiblah and says, "I made an effort to determine it," we tell him that this is not a place for independent legal reasoning (ijtihad). You have what indicates the qiblah to you: you have the mosques, you have the mihrabs, and you have people you can ask about the direction of the qiblah.