I am creating an amortization table using an annual rate (5%) and a monthly-equivalent rate (4.8889%). When you compound the monthly rate 12 times you get the equivalent of compounding the annual rate 1 time i.e. (1+4.8889%/12)^12 = 1.0500 which is the same as (1+5%/1)^1. However, the inverse does not seem to be true – (1-4.8889%/12)^12 = 0.952 whereas (1+5%/1)^1=0.950.