FX-502P with progamming overlay sheet in place

The left most key above the 7 is the xD key used for inputting data into the statistic function. There was no unique statistics mode on the FX-502P unlike many other Casio calculators.

The inverted function of the top right most key is NOP, that is No Operation. On the later FX-601P/FX-602P this position was replaced with the ALPHA mode switch function.