The top line of the display contains information, in very small print, about how your calculator is set up and being used. This Page explains what all the ikons mean, although if you have worked through the other Pages you will already know; if you have not there are links to the Pages where they are explained.
If you are using all the default settings, initially only two items appear in the display, D and Math, but if you look very carefully under good light and with a magnifying glass you can just make out the positions of others where they are greyed-out. Casio fx calculators may share some components, including the display, with other Casio calculators so you may see some greyed-out items in the display which refer to settings not available on fx-83 and fx-85 models.
You may use the DOWN cursor control key to view later calculations
You may use the UP cursor control key to view earlier calculations