Transaction history is easiest to understand when you separate charges from payments.
A charge is money added to an account balance.
You will usually see a charge when Cadence Calendar creates a billing record for a lesson or another bookable service. Charges are how the system records what is owed.
A payment is money received from a family or account holder.
Payments reduce what is owed and help bring the account balance back down.
A typical billing flow looks like this:
If you are trying to understand why an account balance changed, charges and payments are the first two records to check.