Keys:

Clear entry/Clear key

Pressing this key once will clear the last operation and the display.  Pressing that key twice will clear all operations except the memory.

Note:   For clear the memory, press clear then STO.

Note:   Several brands break this function into two separate keys, commonly labeled "clear" and "all clear," where the "clear" key clears the last entry and the "all clear" key clears the display and all pending operations.