A math question that appeared on a first-grade exam paper in Singapore and has since been making the rounds on social media because of its level of difficulty.

The bonus question shows an evenly divided circle with five numbers in it and four corresponding blank circles that are meant to be filled in with the right answers. The directions only say, "Study the number pattern. Fill in the missing numbers."

Photo: HARDWAREZONE FORUM

One Facebook user wrote of the question, "I just finished my course on advanced applied math and I can't solve this. Whoever set this is sick."

Meanwhile, The Strait Times found a near-identical puzzle that appeared previously on a blog run by Gordon Burgin, a self-proclaimed author of math and logic problems. The only difference from the first-grade exam paper and Burgin's version is one number: Burgin's copy is 20 instead of 2.

Called the "Petite Circle," Burgin provided more information on how to solve it and a detailed solution. For those who are up for challenge, check out the problem below:

Here's how to solve it:

Photo: Gordon Burgin/Getty Images