fx991EX Functions, Tables, Regressions and Visualization with QR Code Mini-Math Lesson) - YouTube
Casio FX-991EX Classwiz Non-Programmable Scientific Calculator, 552 Functions with Menu Driven Interface, Black : Amazon.in: Office Products
Found this incredible function on my Fx991EX if you press shift and Option button on left corner it creates a QR code that can be scanned with a phone to see graphing