6/12 = 50%
A value of 50% shows up in everyday life when something is split evenly, like sharing a pizza between two people or getting half off a purchase. It can also describe a survey where half the people choose one answer.
You can picture 50% as half of a whole: imagine filling one side of a glass, shading half a shape, or marking the midpoint on a progress bar. When estimating, ask whether the amount looks roughly equal to the whole divided into two parts.
A common point of confusion is thinking that 50% always means 50 items. It means half of whatever total you are comparing, so 50% of 12 is a different amount from 50% of 100.