What is a session pack in Klasku?

A session pack is how Klasku ties money to attendance: a student holds a pack containing a number of sessions, and attendance marked Present consumes one session from it. The pack belongs to the STUDENT in the class they were placed into, not to the class itself.

That is why remaining sessions are not a figure an admin maintains. It is the result of a consumption history — one row per attendance mark — so every deduction traces back to the session that caused it, and correcting attendance repairs the balance without a manual adjustment.