That would foil me if it was my only memory device. A+B=C is true of ~55 (napkin math) different 3-digit numbers. Plus another 40-ish for A×B=C and 50-ish for A-B=C...
Actually, I’ve heard that on cell phones in EU, you can still dial 911, and it’ll connect. I have had occasions to call 112 before, but it’s always been in big enough emergencies that I didn’t have time to experiment. I’m eagerly awaiting the day when I come across an emergency that’s urgent enough to call 112, but not urgent enough that it can’t wait a little bit for me to try something. It’s a delicate balance