It's the one on the left. We're allowed any calculator that's not programmable and cannot store text. The Elektronika can be programmed though it cannot store a program when turned off.
Nevermind the Casio's ability to solve, integrate, derivate, deal with complex numbers and matrices and more
A kid in highschool figured out how to plot a "memory cleared" screen on his TI-84. The only indication it wasn't a legit screen was the blinking cursor in the top left.
I personally hated clearing the memory on my ti-83 since I tend to have crap tons of useful programs stored.