55. For the purposes of this Division,(a) “daily balance” means the amount that, during a period, is determined at the end of each day by adding the value of any transaction debited to the account since the commencement of the period to the aggregate of the balance of net capital at the end of the preceding period and, where applicable, to the credit charges outstanding at the end of the preceding period, and by subtracting the value of any payment received by the merchant since the commencement of the period;
(b) “average daily balance” means the sum obtained by dividing the aggregate of all the daily balances of a period by the number of days in that period.