Problem: find the simple interest on $ 10000 at 6 % per annum for 12 months ?
Rationale: "p = $ 10000 r = 6 % t = 12 / 12 years = 1 year s . i . = p * r * t / 100 = 10000 * 6 * 1 / 100 = $ 600 answer is c"
annotated_formula: multiply(10000, divide(6, const_100))