This post has been updated.

During an event in Iowa on Tuesday, Hillary Clinton offered a suggestion to improve the nation's schools. "I wouldn't keep any school open that wasn’t doing a better-than-average job," she said. "If a school's not doing a good job, then that may not be good for the kids."

Now this sounds great, except for one downside: It would, taken to its logical conclusion, mean shutting down every school in the country. (As noted by the campaign in the update below, this is of course not the plan.)

So let's say that there are 16 schools in the United States, which is probably a low estimate. We'll use this little school icon (made by Vectors Market) to represent each of those schools. Here:

Alright. Now let's assume that each school is evaluated on a scale from 1 to 100 each year. This isn't exactly how it works, but go with it for the sake of the example. Here are random scores for those 16 schools.

The average of those scores is 58.4. Per Clinton, any school that is not above that average has to get closed. So: Bye, schools!

Now, let's just assume that the schools get the same scores the next year. The new average is 73.9. And: Bye, more schools!

The key point here — the reason that it doesn't matter if we change the schools' scores or not, is this: About half of the schools in the United States will always be at or below average. That's how an average works! (If we used median scores,we’d get a cleaner half-and-half split.)

Continuing on. The new average is 88: Bye school!

The average is now 93. Bye school! Your 91 was sensational a few years ago; now it's in the bottom 50th percentile!

Clinton also stipulated that schools had to be above average  to stay open. With one school, that school's score is the average, and therefore cannot be above that level.

Bye, last school in America!

The good news is that, if this plan is put into action, there will still be a place kids can go and learn math.

Newspaper websites.

Update: Hillary For America spokesman Jesse Ferguson offered the following statement in response to this article:

"A big reason Hillary Clinton was in Keota yesterday was to support smaller, struggling communities and their school districts that face shrinking tax bases. As the only candidate to outline a detailed plan to spur economic growth in rural areas like Keota, she spoke again about Governor Brandstad’s decision to starve Iowa schools, especially rural ones, of critical funding, which could force too many rural schools to close. She also noted that shutting down these schools was not good for Iowa students and communities. Hillary Clinton’s entire career has been a commitment to fixing struggling schools, not shutting them down, and she’s going to continue that if she’s elected President."

All the schools in America won't be shut down after all. That's good.