2nd F and ALPHA
Most keys do up to three jobs. The word on the key is its main job: press 
and you get the natural logarithm. The orange label above the key is its second function: press 
first, then the key, so 2nd F and 
give e to the power x. The teal label is a memory letter or a statistics value: press 
first, so ALPHA and 
give memory F. STO and RCL also use the teal letters. Like the manual, numbers you type are shown as plain numbers, not as keys.