The term 'calculator key' refers to the buttons on a calculator that are used to perform various operations. The crossword solutions for this term include 'PLUS' (4 letters), 'TAN' (3 letters), 'ENTER' (5 letters), 'TOTAL' (5 letters), 'SINE' (4 letters), 'cle' (3 letters), 'SIN' (3 letters), and 'CLEAR' (5 letters). The PLUS and MINUS keys are used to add and subtract numbers, while the TAN, SINE, and SIN keys are used to calculate trigonometric functions. The ENTER key is used to input data into the calculator, and the TOTAL and CLEAR keys are used to display the result of a calculation or to CLEAR the calculator's memory.