When doing math problems on a calculator, you might check and recheck a problem to make sure you have the right answer. If you’ve been pranked with a Wrongulator in the past, chances are you now rework your problem at least five times to make sure it’s right. On the other hand, the appropriately named Redundant Calculator will let you know if your answers are correct two times over.

There really is no reason to combine a calculator and an abacus, but Sharp decided to do it anyway. Even though this is just an extra step, some people enjoy the physical task of moving those little beads to and fro. While I can see how there may be a few people in the world that still prefer to work with an abacus, I can’t think of a single person who would be willing to pay $80 for them.

Credit: Technabob