"small enough" depends on technological factors such as memory sizes and access times. For breaking world records, the iterative algorithms are used less commonly than the Chudnovsky algorithm since they are memory-intensive. The first one million digits of and are available from Project Gutenberg. A former calculation record (December 2002) by Yasumasa Kanada of Tokyo University stood at 1.24 trillion digits, which were computed in September 2002 on a 64-node Hitachi supercomputer with 1 terabyte of main memory, which carries out 2 trillion operations per second, nearly twice as many as the computer used for the previous record (206 billion digits). The following Machin-like formulae were used for this: (Kikuo Takano (1982)) (F. C. M. Størmer (1896)). These approximations have so many digits that they are no longer of any practical use, except for testing new supercomputers. Properties like the potential normality of will always depend on the infinite string of digits on the end, not on any finite computation. Miscellaneous approximations Historically, base 60 was used for calculations. In this base, can be approximated to eight (decimal) significant figures with the number 3;8,29,44, which is (The next sexagesimal digit is 0, causing truncation here to yield a relatively good approximation.) In addition, the following expressions can be used to estimate : accurate to three digits: accurate to three digits: Karl Popper conjectured that Plato knew this expression, that he believed it to be exactly , and that this is responsible for some of Plato's confidence in the omnicompetence of mathematical geometry—and Plato's repeated discussion of special right triangles that are either isosceles or halves of equilateral triangles. accurate to four digits: accurate to four digits (or five significant figures): an approximation by Ramanujan, accurate to 4 digits (or five significant figures): accurate to five digits: accurate to six digits: accurate to seven digits: - inverse of first term of Ramanujan series. accurate to eight digits: accurate to nine digits: This is from Ramanujan, who claimed the Goddess of Namagiri appeared to him in a dream and told him the true value of . accurate to ten digits: accurate to ten digits: accurate to ten digits (or eleven significant figures): This curious approximation follows the observation that the 193rd power of 1/ yields the sequence 1122211125... Replacing 5 by 2 completes the symmetry without reducing the correct digits of , while inserting a central decimal point remarkably fixes the accompanying