There are a few ways to do this. One method is to draw a circle and then fill in exactly one half of the circle. Another method is to cut a rectangle in half following the same idea as the circle. Or you can start off with two equally sized rectangles, and glue them together to form a larger rectangle. If one of the rectangles was shaded in, then the shaded region is 50% of the total area of the larger rectangle. If you prefer to work with countable objects, then draw out 8 cars (or any object really) and shade 4 of them to represent 50%. I'm sure you can probably get more creative with how to represent 50%
