It's an argument as old as time, well as old as Italy, anyway. Just how big a pizza should you order to get the best deal?
The small one? The medium one? The one as big as your house? Well, today I'll show you. It's the "yeast" I can do.
Here are five things to know:
- Unless you're ordering one of those fancy artisanal pizzas, most are round—basically, a circle. And every circle has something in common. It's pie! This kind of PI. The mathematical number 3.14, which explains the number of times the diameter — the straight line that passes from side to side through the center of the circle — can wrap itself around the edge. That magic number is always the same, 3.14 times (it's a longer number than that, but let's just stick with this for now).
- So you want to figure out which pizza is the best value? Which means how much it costs per square inch? Well, here's a formula you need to know: PI R squared. The R is the radius — the length of a straight line from the circle's center to the edge — which is also half the diameter—got that?
- Say you have three pizzas: a 6-inch small at $5, a 12-inch medium at $10 and a monster-size 14-inch at $12 bucks. Which is the best value? Let's slice 'em up.
- The personal is $5 and only 6 inches in diameter, so the radius is half that at 3 inches. PI 3.14 x 3 inches, squared = 28.26 and $5 divided by 28.26 = 17 cents per square inch of pizza. Bound to be the cheapest, as it's only $5, right?
- Using our equation, we find: The medium 12-inch costs $10 and, therefore, is around 9 cents per square inch. And the monster-sized 14-inch is $12, which equals about 8 cents per square inch. So now you can say "good pie" to the personal pizza because the monster-sized one is the way to go in terms of value!
So the next time you and your pals get into it over pizza, just remember the formula: PI R squared. Because, if you don't and you order the more expensive small pizza, your pals might think you are some kind of "weird-dough."