Student's answer to math question sparks discussion after teacher marks it as incorrect

Mathematics can be a source of confusion for many due to its complex concepts and abstract nature. Complex equations, diverse formulas and intricate problem-solving methods can be quite challenging for many and can lead to big misunderstandings. @MarkLTighe recently shared a tweet that is sure to get one thinking and quite confused. The post reads, "Hmm. Controversial ruling from the múinteoir here on 'How many corners does a semicircle have.'" In the picture, we get to see his child's maths textbook with a question about how many corners a semicircle has.

The child has given the answer to be two corners, which the teacher marked as incorrect. The teacher's ruling proved to be quite confusing, which is why Mark Tighe posted it on X to get a second opinion. Once the post went up, the internet seemed quite divided on what the correct answer was. @NIAMHBL said, "In geometry, a semicircle is a plane figure that is formed by dividing a circle into exactly two parts. A corner is a place or angle where two sides or edges meet. So the answer is yes, the semicircle has two corners where the curved semi-circumference meets the straight diameter."

There were many other answers that sided with the kid's answer of two corners. @MuinteoirChris, a teacher, clarified, "I reckon there'll be some arguing about this, but your child seems to be right. If the definition of a corner is where two lines meet but doesn't specifically state it has to be straight lines, then a semicircle has two corners. But if the definition being used is two straight lines, then it's 0. @sharemath, you're my most trusted maths expert on this site. Any insight?" The debate then came to be centered around the definition of a corner.

@PoliticsWatch14 commented, "A semicircle, by definition, has no corners because corners are points where two or more edges meet at an angle, and the perimeter of a semicircle consists of one straight edge called the diameter and one curved edge called the arc. Therefore, the correct answer to the question would be that a semicircle has 0 corners." Another individual, @cathalcampbell, clarified, "The consensus in the online geometric community is that a semicircle has two corners. Teacher wrong, child correct."

Nobody seemed to have a concrete answer to the seemingly simple question. But, it goes to show that maths need not be everyone's cup of tea. This is certainly not the case for 6-year-old Nathan Katcher, who has become famous for making mathematical calculations in the blink of an eye. The red-haired boy, who is currently in the first grade, is astounding the internet with his blazing-fast ability to solve difficult mathematical equations.

In one of the videos shared by his mother, Rachel, on TikTok, viewers witness the boy easily solving a very complex equation. The problem goes as follows, "The square root of 81, times 10, divided by 2, times 3, minus 20, plus 15, minus 30, times 10, divided by 2." Such a problem would have most adults scratching their heads but Nathan was able to solve it within 44 seconds to arrive at the correct answer of 500. He continues to impress people with his amazing math skills and we will hopefully get to see him conquer bigger math problems as he grows up.

Editor's note: This article was originally published on November 28, 2023. It has since been updated.