A classic calculator that is suitable for everyone. 1) M＋ = Add the current value to (or from) the stored value in the memory register. 2) M- = subtract the current value to (or from) the stored value in the memory register. 3) MR = Recall the current memory register value. 4) MC = Clear the memory register (set to zero). 5) C/AC = Clear the screen ( set to zero), press it one more time to clear all. 6) Long press the screen result to copy.