This will take you far -- the important thing about binocular vision is that it allows an organism to get a sense of distance to whatever it's looking at (it's called parallax, but faster).
You're getting fitted for glasses. The optometrist tells you to cover one eye. You do, you can't read anything, and he makes some crack about your mother's honor because he thinks that you're stupid. You have one eye closed and you try to punch him, and WHIFFF your fist lands on empty air, even though it's right in front of his face.
You drop the eye-cover-spoon-thing, and think, "Oh, that's why." You lead forward six inches and club him. He drops, you kick him in the gut for good measure, then drive home and look for a different doctor.
Thus, superior binocular vision. You might do something like that. Make a number of different targets of different sizes, set them at different distances from your friends (do each distance round with each friend), and see if they can poke it with a stick with one eye, then both eyes. Also, using both single eye and double eye, just have them estimate the distance, using the different sized targets (there will be a bunch of error here, because some people are better at that kind of estimate than others -- for instance, I suck at estimating distance, height, and age).
ALSO -- this will illustrate the concept of dominant eye. Have all cover their left, and try to hit it. Then everyone covers their right, and try to hit. Most, if not all of your friends will barely hit or even completely miss the target with their right eye covered.
But you uncover both eyes, and BAM -- unless your friends really *are* morons, they'll beat the stuffing out of a pinata.
In the end... (I've gone on too long, sorry), binocular vision gives you distance. This is important for a predator looking for prey, and for the prey animal trying to avoid the predator -- and my great grandfather E+100 in Europe deciding if he can take his clan and hike it across that open field before that storm that's rolling in sets in.