Terminated: unknown
The "Solar Cell" on this calculator is actually completely fake. Really. I even opened the case to check, it’s just a decorative piece of plastic. Given the amount of detail I wonder if producing a calculator with a fake "Solar Cell" actually cheaper. Makes me wonder as well if there’s anything in the manual about the fake "Solar Cell".
Negative numbers are indicated using a "-MINUS" symbol at the top-left of the display. There are two very small buttons, one for calculating square roots, the other to change the sign of a number.