Here is a modified version of your code..... 1 stor A Lbl C (1+1/A)^A sto B DISP B DISP A A+1 sto A PAUSE GOTO C What was happening was that where you had a*10 stor A..... This was overflowing the calculator. Say a is 10, then.... 1 10 2 100 3 1000 4 10000 5 100000 And this is the number that you are using as a power! (ie. n^(a*10)) Hope that helped! -Justin SMith -- <