Before Nadia, the highest score anyone had ever got in Olympic gymnastics was 9.95. Most people thought a perfect 10 was impossible - that there would always be some tiny wobble or step out of line. The scoreboard at the Olympics wasn't even built to show three digits. When her score came up, it read '1.00' because the screen could only fit two digits! The crowd cheered when they realised the score really was 10.00.
Nadia went on to score six more perfect 10s at those same Olympics, and won three gold medals. She was 14 years old, just a few years older than most of the children reading this lesson. She trained for hours and hours every day, but she also did normal kid things like school and homework.
Romania has been brilliant at gymnastics ever since. The country has won dozens of Olympic medals in the sport. Romanian coaches are known for being patient and strict - they teach gymnasts how to break very hard moves into tiny steps and learn each one slowly.
Nadia is still alive today, in her sixties, and travels the world helping children learn gymnastics. She often tells them: nobody is born being able to do a perfect 10. You start by being able to do nothing, and you practise every day, and one day you can do something that looked impossible.