Question: how to calculate variance and standard deviation on ba ii plus?
Answer: press 2nd, 7 (Data)
press 2nd CE/C to clear the worksheet.
enter data into the X fields (X01, X02, etc.). ... 
press the down arrow twice, then type the second observation and press Enter. ... 
press 2nd, 8 (Stat)
press 2nd, Set. ... 
press the down arrow repeatedly to display statistics one at a time.