TVM16a - Future Value of a Single Sum - Unknown Number of Periods Previous Home Next tvm16a - Future Value of a Single Sum - Unknown Number of Periods from Richard Campbell Audio Transcript Richard wishes to become a millionaire. His investment account has a balance of $150,000 and has guaranteed interest of 9.5%.How many years does Richard leave this balance invested in his fund to achieve his targeted $1,000,000?First, we input the variables.PV is $150,000.The RATE is 9.5%.The future value, FV, is minus $1,000,000.The unknown here is the number of periods, NPER.We go to Formulas tab.We look for NPER.We click on RATE.We click on PV,we click on FV.We hit OK.And the number of periods, NPER, is 21.