Chosen Solution
How to unhang calculator
Remove Battery Since you can’t interact with the calculator at all, start with removing its battery by following the guide I have added below. You can skip replacing the battery, just put the same battery back again. This will force the calculator to turn off. Casio FX-991ES Plus Battery Replacement If problem continues If it still freezes when you do that, redo the process of removing the battery and then do the following steps to factory reset the calculator. When the calculator is on. Step 1: Press SHIFT and then 9 Step 2: Press 3 to select the “Reset All” option Step 3: Press = to confirm Step 4: Press the AC button Hope it works after this! :D
