Casio FX-991DE X
Batteries, Solar cells
Casio FX-991DE X
Batteries, Solar cells
The whole menu is in English instead of German. If you are being taught in German, it may be difficult to understand at the beginning which menu item you have to select. Unless you know words like 'vector calculus' or 'cumulative normal distribution' or 'binomial density' in English. But I think that is the only difference.