Regulated Loans and Revolving Loan Accounts. (1) With respect to a consumer loan other than a regulated loan or a loan pursuant to a revolving loan account, a lender may contract for and receive a loan finance charge, however calculated, not in excess of ten percent (10%) per year calculated on the unpaid balances of the principal according to the United States rule. (2) For the purposes of this section, the term of a loan shall be calculated in terms of calendar months beginning with the date the loan is made. Differences in the lengths of months are disregarded. Fractions of a month are treated as a full month if more than 15 days, and if 15 days or less, are disregarded.