On August 7, at the Kuboid Museum of Mathematics in Kyiv, 17-year-old Kateryna Zlobina set a national record for Ukraine among children by reproducing 400 decimal digits of the number π by hand . The record was first recorded in the written reproduction of a numerical sequence; previously, records in this category in Ukraine were set only by oral recitation .
“Despite the full-scale Russian invasion, Ukrainian students continue to set ambitious goals and achieve them. Today’s record is a vivid confirmation of this. I am especially proud that our Museum of Mathematics “Kuboid” is becoming the place to set a national record for the second time. Last year, before the first celebration of the International Day for Engaging in Science for Sustainable Development — an international UNESCO day initiated by Ukraine — Borys Vaskovets set a national record for Ukraine among children by orally reproducing 300 digits after the decimal point in the number π. Today, Kateryna Zlobina added to the list of national records by reproducing 400 digits of the number π in writing. These are achievements that testify to the sincere interest of Ukrainian children in mathematics and the desire to develop their abilities,” shared the President of the Small Academy of Sciences of Ukraine, Academician of the NAS of Ukraine Stanislav Dovgy.
Kateryna was born in Severskodonetsk, Luhansk Region. Since childhood, she has been fascinated by mathematics, creativity, and sports. In the junior grades, the girl participated in mathematical competitions, was engaged in sports orienteering, and later - in Olympiad mathematics. After the start of the full-scale invasion, the girl and her family left for Germany, but continued to study online at her native school. Later, the family returned to Ukraine and settled in Kyiv. Here, Kateryna completed her studies at the Kyiv Lyceum, became a prizewinner of the city stage of the Competition-Defense of Scientific and Research Works of the Small Academy of Sciences in the mathematics section , and is currently a second-year student at the State University of Trade and Economics.
The story of her fascination with the number π began a few years ago quite by accident. At first, Kateryna only knew the familiar "3.14", later in math class she memorized a few more decimal places, and in seventh grade she came across a video that helped her easily learn the first twenty digits. At that time, it was just an interesting memory exercise, which later turned into a real passion.
A new stage began in the tenth grade, when the girl transferred to a Kyiv lyceum, where Pi Day was celebrated. The day before, Kateryna decided to learn fifty decimal places, and a year later she brought their number to one hundred. Only after she learned about the current national record at the end of 2025 did she realize that her result was close to the record. It was then that the idea arose to try to set her own Ukrainian record.
Preparations for setting the record lasted six days. During this time, Kateryna not only repeated the already known hundred decimal places, but also memorized three hundred new ones. She submitted an application to the National Register of Records on July 22.
The girl uses several methods to memorize. She learned some numbers using songs, others through her own associations, patterns, visual images, and personalization of numbers. According to Kateryna, her memory combines melodies, text, individual associations, and "dry" numbers at the same time, so it is much easier for her to reproduce the entire sequence in writing than orally.
"The most difficult stage for me was the beginning of studying the fourth hundred. Not technically, but psychologically. I had to have time to set the record before my 18th birthday, which was a month away. Considering the time for consideration of the application by the National Register of Ukraine, I understood that I had to do it in a week. Because I had to learn everything very quickly, I was emotionally tired. I still wanted to achieve my goal, but I couldn't force myself to start preparing - my memory refused to work. I gave myself a day off, after which I tried to learn the last hundred numbers again, and then everything worked out," notes the new record holder Kateryna.
