Cash
With more and more people choosing to pay with credit cards or online money transfer apps like Paypal and Venmo, the use of cold hard cash is slowly phasing its way out of our system. Cash seems to only be good for tipping at bars or restaurants, unless you tip right on the receipt. Think of how much slimmer our wallets will be.
Calculator
The last time anyone used a real calculator was probably high school. Can you name a single capability your smartphone doesn't have these days? Most smartphones come with a builtin calculator that can do everything from basic functions to graphs.