Notes: "The Casio model 450 calculator is a solar powered, full function scientific calculator with some of the buttons on the calculator body, and even more buttons (membrane type) on the flap of the plastic case. Several functions, including base conversions, are done using the “mode” button and the table underneath the display. What’s remarkable about this particular calculator is that while the plastic of the case has stiffened with age, the hinge has not cracked and the buttons on the flap still work."
