Q:
# How many digits of pi have been calculated?

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### Quick Answer

**According to Numberworld, 12.1 trillion digits of pi have been calculated, as of December 2013.** This was achieved after 94 days of computation; however, 12 of those days were lost to hardware issues. The previous calculation that achieved 10 trillion digits took 371 days to complete two years prior.

Credit:
The Washington Post
The Washington Post
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As of 2014, the world record for digits of pi memorized is held by Chao Lu from China. He spent four years practicing and was able to recite 67,890 digits of pi from memory. The recitation happened on Nov. 20, 2005, took just over 24 hours to complete and was documented on 26 video tapes.

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Q:
## What is pi?

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Full Answer >**Pi is the ratio of a circle's circumference to its diameter.**The number pi, symbolized by a Greek letter, has a constant value that approximately equals 3.14. The distance around any circle when divided by its diameter always gives this exact result.Filed Under: -
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## What is the value of pi?

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Full Answer >**The approximate value of pi, which is the ratio of a circle’s circumference to its diameter, is 3.14159265, according to Collins World English Dictionary.**It is impossible to represent its exact value fully and accurately since it is an irrational number with an unending, non-repeating decimal.Filed Under: -
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## Is Pi rational?

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Full Answer >**Pi is not a rational number.**It is considered irrational. A rational number is able to be written as a fraction with integers for both the numerator and denominator.Filed Under: -
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## What is pi used for?

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Full Answer >**Pi is used to find the circumference and area of a circle.**It is also used to find the volume and surface area of a sphere, cone and cylinder. Pi has applications that go beyond geometry as well, such as statistics and probability.Filed Under: