On January 1, 2010, Huber Co. sold 12% bonds with a face value of $600,000. The bonds mature in five years, and interest is paid semiannually on June 30 and December 31. The bonds were sold for $646,200 to yield 10%. Using the effective-interest method of amortization, interest expense for 2010 is? The Answer is 64,436. I don't understand why though. I keep getting 64,620. Please help me out.