Logarithms in base 10 and in any base
The log key is the logarithm in base 10. Press 
, type 1000, 
, and 
: 3. For any other base, use the key with log and two boxes. Press that 
, type the base 2, press 
, type 16, and : the logarithm of 16 in base 2 is 4. Where you press the right key decides what a power applies to. Press the , type 2, , 4, then 
, and : the log of 4 cubed is 6. But press the , 2, , 4, then once more to leave the logarithm, then , and : now the whole logarithm is cubed, and the answer is 8.