What does the “EX” function do on this calculator? For ref, it's the one in from the top right near the OFF button. : r/calculators
Casio fx-300W Power Scientific Calculator Case with Cover and Quick Ref | eBay
Sharp Desktop Calculator 8 Digit 4 Key Memory Battery/Solar Power 77x10x125mm Black Ref EL310ANWH - ASAP Distribution - Film and TV Consumables Suppliers
RREF Calculator with steps | Reduced Row Echelon Form Calculator