science

Lee Jeonghee

Lee Jeonghee is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Lee Jeonghee rather than just read about it. In short: Lee Jeonghee (Korean: 이정희; born 23 February 1963) is a South Korean abacus master. She is the only known soroban abacus master to have reached the eleventh dan.

Key takeaways

Lee Jeonghee belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Lee Jeonghee to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Lee Jeonghee from memory before moving on to harder problems.

Reference excerpt

Lee Jeonghee (Korean: 이정희; born 23 February 1963) is a South Korean abacus master. She is the only known soroban abacus master to have reached the eleventh dan. She is also known as Abacus Master (주산왕) in South Korea.

Biography Lee began training with the soroban abacus in fifth grade. In her first year of high school, she obtained the 11th dan. 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. 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. 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. By the end of the program, almost all of the students were able to mentally solve an addition problem of fifteen 5-digit numbers in under thirty seconds. In 2013, Lee appeared on the South Korean television program Miracle Korea. During the episode, she demonstrated her ability to do Flash Anzan, adding together a total of fifty 4-digit numbers individually flashed on a screen for less than one second each, while simultaneously being interviewed by the hosts. During the same episode, she mentally added fifty 25-digit numbers in 94 seconds. In 2016, Lee competed in the Mental Calculation World Cup. The Mental Calculation World Cup 2016 was held from 23–25 September 2016, in Bielefeld, Germany where 31 mental calculators from 16 countries participated. She won in multiplying two 8-digit numbers and was recognized as the Most Versatile Calculator (having the best score for solving another 5 unknown "surprise tasks"). She placed 3rd in the overall competition (a combination of all 10 categories). 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. She has been a resident of Fort Lee, New Jersey.

References

Worked examples

Example 1 — a first encounter with Lee Jeonghee

Start with the simplest possible case. Write down what Lee Jeonghee claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Lee Jeonghee before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Lee Jeonghee ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Lee Jeonghee

In research: Lee Jeonghee appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Lee Jeonghee in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Lee Jeonghee is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1963 births, Abacus, Living people, so understanding it makes those chapters shorter.
In everyday life: Look for Lee Jeonghee outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Lee Jeonghee in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Lee Jeonghee means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Lee Jeonghee out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Lee Jeonghee in simple terms?

Lee Jeonghee (Korean: 이정희; born 23 February 1963) is a South Korean abacus master. She is the only known soroban abacus master to have reached the eleventh dan.

Why does Lee Jeonghee matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Lee Jeonghee?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Lee Jeonghee.