Igor Alexeyevich Shelushkov (born – ?) was a

Soviet The Union of Soviet Socialist Republics. (USSR), commonly known as the Soviet Union, was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 until Dissolution of the Soviet ...

mental calculator Mental calculation (also known as Mind, mental computation) consists of arithmetical calculations made by the mind, within the human brain, brain, with no help from any supplies (such as pencil and paper) or devices such as a calculator. People m ...

. He mentally extracted

roots A root is the part of a plant, generally underground, that anchors the plant body, and absorbs and stores water and nutrients. Root or roots may also refer to: Art, entertainment, and media * ''The Root'' (magazine), an online magazine focusin ...

of large numbers and calculated the number of syllables and characters in a given verse by listening. Shelushkov was featured in the 1968 Soviet

popular science Popular science (also called pop-science or popsci) is an interpretation of science intended for a general audience. While science journalism focuses on recent scientific developments, popular science is more broad ranging. It may be written ...

film ''Seven Steps Beyond the Horizon'', where he mentally extracted the sixth root of a 12-digit number and the 77th root of another multi-digit number. Shelushkov also competed with the Soviet

third generation computer Third or 3rd may refer to: Numbers * 3rd, the ordinal form of the cardinal number 3 * , a fraction of one third * 1⁄60 of a ''second'', i.e., the third in a series of fractional parts in a sexagesimal number system Places * 3rd Street (dis ...

Mir. He extracted the 77th root of a 148-digit number in 18 seconds, while it took about 10 minutes to program the related operation for computer. Shelushkov was a postgraduate at Gorki Polytechnic Institute (now Nizhny Novgorod State Technical University). According to Shelushkov, he used the memorized

logarithm In mathematics, the logarithm of a number is the exponent by which another fixed value, the base, must be raised to produce that number. For example, the logarithm of to base is , because is to the rd power: . More generally, if , the ...

ic table for calculations. His abilities were mentioned by Russian mathematician Vladimir Tvorogov, who attended one of his performances, and by psychologist Artur Petrovsky. Shelushkov's subsequent fate is unclear.

References

Mental calculators Soviet mathematicians Year of birth uncertain 1940s births Living people {{mathematician-stub