Some Facts about Pi

  • Pi is the first letter of the Greek word perimeter meaning distance around.

  • In 1737, Euler used the symbol for pi to be equal to the ratio of the circumference to the diameter in a circle.

  • A brief history of pi:
    • Biblical References: I Kings 7:23 II Chronicles 4:2
      In Kings, it states, "And he made a molten sea, ten cubits from one brim to the other: it was round all about, and a line of thirty cubits did compass it about."
    • 240 B.C. Archimedes found pi to be between 223/71 and 22/7

    • 150 A.D. Ptolemy found pi to be approximately 377/120 (or 3.1416)
    • 480 A.D. In China, pi was found to be approximately equal to 355/113 or 3.1415929 ...

    • 1150 Bhaskara (a Hindu) gave 3927/1250 as an accurate value of pi
    • 1579 Viete used polygons having 393,216 sides to evaluate pi correct to 9 places
    • 1610 Van Ceulen used 2^62 sides to compute pi to 35 decimal places

    •                          (2)(2)(4)(4)(6)(6)(8)... 
1650 John Wallis  pi/2 = ------------------------- 
                         (1)(3)(3)(5)(5)(7)(7)... 
                        
    •                            1     1     1
1674 Leibniz   pi/4 = 1 - --- + --- - --- + ...
                           3     5     7

    • 1897 Indiana's General Assembly considered Bill No. 246 to legislate the value of pi. The value considered was sixteen divided by the square root of 3, which equals 9.2376... which isn't even close! Luckily, a professor from Purdue happened to be at the capitol when this bill was introduced, and he advised the senators of their error.
      Click here to find out more about this bill!

    • 1949 ENIAC (first modern computer) spent 70 hours to compute pi to 2,037 places

    • 1986 Cray-2 Supercomputer computes pi to 29,360,128 decimal places (it took 28 hours and 12 trillion arithmetic operations)
    • 1988 Yasumasa Kanada of the University of Tokyo computed pi to 201,326,000 decimal places

    • 1990 The Chudnovsky brothers computed pi to 1,011,196,691 decimal places
    • 1997 Pi is computed to 51,539,600,000 decimal places

    • On April 4, 1999, Pi is computed to 68,719,470,000 decimal places by Yasumasa Kanada and Daisuke Takahashi at the University of Tokyo.

    • On September 20, 1999, Pi is computed to 206,158,430,000 decimal places by Yasumasa Kanada and Daisuke Takahashi at the University of Tokyo.

    • In September 2002, Pi is computed to 1,240,000,000,000 decimal places by Professor Yasumasa Kanada at the University of Tokyo. It took over 400 hours on a Hitachi Supercomputer.
      Click here to read the news release!

  • The 1983 Guinness Book of World Records lists Rajan Mahadevan as having recited 31,811 places of pi from memory (it doesn't say why he did this ... )
    Click here to see a news release about a Virginia student who memorized pi to 8,000 digits

  • Here are some Mnemonics to help you remember the digits of pi,
    which begin 3.1415926535897932384626433832795...

    • Yes, I know a digit.

    • May I draw a circle?

    • Wow, I made a great discovery!

    • Now I need a verse recalling pi.

    • How I wish I could enumerate pi easily today.

    • May I have a large container of coffee right now?

    • May I have a large container of coffee -- sugar and cream?

    • Sir, I need a large microwave to simmer, broil, and roast.

    • Hey, I need a large motorboat to rescue women and girls.

    • How I wish I could recollect pi
      Eureka! cried the great inventor.
      Christmas pudding, Christmas Pie
      Is the problem's very center.

    • God! I need a drink --
      Alcoholic of course --
      After all those lectures
      Involving radical equations.

    • See, I have a rhyme assisting
      My feeble brain, its tasks ofttimes resisting.

    • See, I have a rhyme assisting
      My feeble brain, its tasks ofttimes resisting.

    • Sir, I send a rhyme excelling (3.14159)
      In sacred truth and rigid spelling (265358)
      Numerical sprites elucidate (979)
      For me the lexicon's full weight (32846)
                  ... From ask Marilyn, 5/30/2004

    • Que j'aime a faire apprendre un nombre utile aux sages
      Immortel Archimede, antique ingenieur,
      Aui de ton jugement peut sonder la valuer?
      Pour moi ton probleme eut de pareils avantages.

      (The author was a French mathematics professor names Lucas.
      A literal translation of his rhyme:
      How I would like to express a number useful to the wise.
      Immortal Archimedes, ancient engineer,
      Who can appreciate the value of your judgment?
      For me your problem had equal advantages.)

  • Click here to see a Tribute to 9/11 Using Pi

  • A palindrome: I prefer pi.

  • Einstein's birthday is March 14, which is the 3rd month, 14th day or 3.14

Links:

Math Facts Page

Handley Math Home Page