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Tweet about restaurant’s pizza miscalculation goes viral. Does the math check out?

This pizza math problem keeps making the rounds (get it?) on social media.
Pizza and quadratic equations: a match made in heaven.
Pizza and quadratic equations: a match made in heaven.TODAY Illustration / Getty Images

Who knew that pizza night was a geometry quiz waiting to happen?

On June 29, a tweet went viral. Like, really viral. The user, @cretiredroy, told the story of a visit to a pizzeria that turns into a clever conundrum of mass, geometry, and deals and steals. 

“I ordered a 9-inch Pizza,” said @cretiredroy in a tweet that garnered an astonishing 50,000 retweets and more than 197,000 likes in less than a week on the first tweet alone. “After a while, the waiter brought two 5-inch pizzas and said, the 9-inch pizza was not available and he was giving me two 5-inches Pizzas instead, and that I am getting 1 inch more for free! I requested the waiter to call the owner.”

The Twitter user goes on to say that the owner watched him use a mathematical formula to calculate the area of a circle. After recounting calculations that may give you unnerving flashbacks to 10th grade geometry class, @cretiredroy comes to the conclusion that while two 5-inch pizzas seem to the layman like they would be more pizza, math proves quite the opposite. In fact, the math works out that even if he were to get three 5-inch pizzas, the area of the pies would equal less pizza than the one 9-incher he originally ordered.

Pizza math aside, users were quick to express their doubt that this story ever happened, as is common practice when anything goes viral. But this time, users came with receipts.

“Sir please get a life for yourself and dont hanker for likes and retweets at this age by copy pasting stuff from the internet,” one Twitter user responded.

“Amazingly this exact situation happened about 40 times to other people besides you,” another Twitter user replied, embedding a tweet containing the same story posted a day earlier. There are a bevy of pizza places that don’t have the forethought to keep extra dough in stock, especially around math whizzes, it seems! 

If this whole story sounds as far-fetched to you as other users on Twitter, well, that’s because it is — and not only because it's unlikely that a pizza shop owner has the patience to sit through a math lesson while serving enough customers to have low stock on pizzas. It turns out, the Twitter user did indeed fabricate the story.

“This incident never happened,” @cretiredroy confirmed in a direct message on Twitter to TODAY Food, punctuating this message with the embarrassed face emoji.

Since the original poster is a proven viral fibber, you may be wondering if the math involved was correct at all. We were, too, so we decided to consult a few experts to see how this cheesy situation may play out in real life.

“It does seem a little improbable,” Matt S. Fairbanks, assistant professor of physics at California State University Maritime Academy told TODAY.

“The math being used in the tweet is geometry,” Katie D’Alto, a math teacher in Long Island, New York, told TODAY. “The inches of the pizza are given as the diameter, and the radius is half of the diameter.”

Fairbanks added that math for calculating the area of the pizzas seems accurate. “I suppose the person should really be calculating volume, but it’s a reasonable assumption that the thickness of all the pizzas is the same,” he said.

All of the experts we spoke to agreed that the math was accurate, and in their own math magician fashion, completed the formula themselves to prove so.

“The area of a circle is calculated using the formula A=πr²,” Jordan Fulmer, a mechanical engineer-turned-real estate investor in the Huntsville, Alabama area told TODAY. What Fulmer means in non-math English is that “area equals pi times radius squared.” Using that formula, Fulmer says the area of a 9-inch pizza would be about 63.6 in², and the area of a 5-inch pizza would be about 19.6 in². 

“If he accepted the two 5-inch pizzas, he would be getting about 39.6 in² of pizza, much less than the 9-inch pizza,” Fulmer said, adding that there is something to be said about the crust-to-topping ratio of the conflicting pizza orders, and asserting that you would be getting fewer toppings and more crust with the smaller pizzas. If your mind is a little blown at the fact that you never would have conclusion after a century's worth of freshman algebra, you’re not alone!

“In order to make it worth it, the manager had to give the customer four pizzas,” D’Alto concluded.

“It all has to do with the relationship between circumference and area,” Fulmer added.

"Total weight of the pizzas is another reasonable measure, but that would be missing that some ingredients," Fairbanks said. "The toppings are higher value and potentially higher tastiness quotient compared to the crust, though I imagine the calculation would come out in the 9-inch pizza's favor again."

All in all, the one thing that the math experts didn’t agree on at all was what they would do if put in the same situation, each having their own perspective on the way they would handle it.

“I would have done the same thing,” Fulmer said of the original poster’s fictional actions. “Not to be rude, but just to get what I’m paying for.”

“As an introvert, I wouldn’t say anything,” D’Alto said. “But, I would laugh about it with my friends after I did the math.” 

“I’d be unlikely to break out a pencil and piece of paper to show how incorrect the restaurant is,” said Fairbanks. “I don’t think anyone comes out of that feeling happy. I’d maybe leave a comment card.”