It's a peculiar format for a bank reconciliation, but I think I understand it.
Think of the cash book as a T-account with debits on the left and credits on the right.
To reconcile ...
The solution explains the format of the cash book and how to extract the information for a bank reconciliation. The reconciling amounts are listed to arrive at a reconciled balance of cash. Also included is an explanation about why the reconciling items appear and how they would disappear.