Use the ‘new num’ button to start a new calculation. Click the operator to change it. The operator cycles through plus, minus, times, divide, and back to plus again, ready for the next loop. Any letter nulls the whole number to 0 Negative numbers are usable Any other sign are not usable A minus not at the front is not usable 0 / 0 = NaN Any number except 0 / 0 = infinity 0 / any number except 0 = 0
