[2] In 2007, Lee opened up an abacus training academy in Korea, where she has taught thousands of students, some of whom travel to the country solely to participate.
In 2001, Lee represented South Korea in the 20th International Abacus Competition and finished in first place in the singles category.
[2] In 2008, Lee appeared on the South Korean television program Star King with a group of children ages seven to nine, whom she had taught for a 100-day period.
[3] Her students, selected for the program after their parents described them as distracted and underachieving in school, displayed significant improvement in mental calculation skills, as well as in focus and attention.
In November 2016, Lee dominated the mental calculation events at the Memoriad competition in Las Vegas, winning the gold medal in the categories multiplication, addition, division and flash anzan.