a simple explanation would be as follows: suppose that the total finance charge for a 12-month loan was $78.00. that figure is representative of the sum of digits by adding the numbers together, i.e., 12,11,10,9,8,7,6,5,4,3,2,1 = 78. if a person repaid a consumer loan after 3 months, the financial institution would refund the sum of the "remaining" digits...(i.e. 9,8,7,6,5,4,3,2,1 or $45.00. in essence, they would retain the first three (3) numbers...12,11,10 or $33.00. thus the consumer would not receive as much of a refund if it were divided equally by 12 months ($6.50 per month). under this scenario they would have received a refund of $58.50, which is more beneficial than the $45.00 refund.