CASIO PRIZM FX-CG50 Color Graphing Calculator : Amazon.com.tr
Update: It really does go without saying, the FX-CG50 is a beast of a calculator. But my trusty FX-991EX is still good for a lot of things. They are both good calculators. :
fx-CG50 - Casio Calculators
Casio fx-CG50 9 Simultaneous Equations linear and non-linear - YouTube
fx-CG50 - Casio Calculators
Casio FX-CG50 Colour Calculator Black | Kidinn
fx-CG50 PRIZM® Color Grapher | Graphing Calculator | CASIO