As a child, you probably asked a lot of questions.

Are we there yet?
Do I have to?
Where do babies come from?

Though, perhaps, one of the most perplexing questions you asked your young self was one that came up when wandering around at a fair, an open house or a party:

How many jelly beans are in the jar?

jelly bean

Photo by Michelle Lin

The mysterious jar of candy always perplexes small children. Thrilled by the idea of winning the jar if they guess correctly, they eagerly throw out their best guesses. There is, however, an actual art to this–one that many adults haven’t even perfected.

At our Spoonfest event earlier this month, we had one of these jars, filled to the top with an unknown amount of jelly beans (unknown even to us because we counted the beans afterwards). People threw out all sorts of guesses, ranging from 72 to 607. The correct number was 326.

jelly bean

From L to R: Crystal Shi, Steven Chen, Han Phan | Photos by Elizabeth Layman

Much to our surprise, we had a three-way tie. Crystal Shi guessed 327, while Steven Chen and Han Phan guessed 325. All three were gracious winners and willing to share with us their best candy-jar guessing advice.

1. Start by counting the number at the bottom of the jar.

As Han points out, “It’s usually best to ask first if it’s okay to pick the jar up.”

2. Count how many layers of jelly beans there are.

Then, as Crystal says, “Just multiply that bottom number by the number of layers.”

3. Add a “buffer.”

This buffer is an extra few jelly beans added to your total number, and it’s especially important if the jar isn’t completely cylindrical, as was the case with ours.

Extra tip:

Don’t assume that it’s a “clean” number. Steven says that he got to his guess by following the above steps and then assuming we’d put in a clean number of jelly beans (325). Fortunately for him, that mindset landed him only one bean away from the actual number.

If we had counted the jelly beans beforehand, we may have been tempted to make it a cleaner number–but as luck would have it, that didn’t happen. This seems to have made it particularly challenging for other contestants since many of them guessed clean numbers, as well. Also, oddly enough, most of our guessers didn’t expect the correct number to be an even one, though we aren’t sure why.

We suppose the jelly bean guessing jar will always be a little mysterious, and some questions surrounding it will forever remain unanswered. However, we hope that these good guessers’ tips will help you out the next time you’re faced with one of these sweet conundrums.