5. Calculator
This device does not need any introduction as every middle schooler knows its importance in our lives. The first electronic calculator was created in the 1960s, and the pocket size version became available in 1970s. From students to researchers to scientists, everyone carries a calculator these days and it would be hard to find a cell phone without a pre installed calculator app on it.
6. The Bar code
This boring set of black and white lines was developed by Norman Woodland, but they can be found on almost every single item in the grocery store. At first glance, it seems hard to see how they could possibly make any impact on the world, but they have fundamentally changed the way we shop.
