Power OFF after a few minutes if no button is pressed. If a result is too big to show in the LCD, the calculator stops and displays E. Press ON/C»CE to continue. Metal Carrying Case - Protects the calculator wherever you go. +/- Key - Press to change the displayed number from positive (+) to negative (-) or from negative (-) to positive (+).MINUS -is displayed when the value is negative. MEMORY FUNCTIONS [M+] Press to add the displayed number to memory MEMORY is displayed. [M-] Press to su