A Child is Crying (Mind Webs, SF Radio Drama) by John D. Macdonald

The child could read, write and carry a conversation when he was thirteen months old, and at two and a half he was doing quadratic equations. At four, completely on his own, he composed theories regarding non-Euclidean geometry and theories of relativity that paralleled the work of Einstein. Now he's seven, and the government wants him.
Story published December 1948 ~ Thrilling Wonder Stories
This work is in the public domain. It was published in the United States between 1923 and 1963, and the U.S. copyright was not renewed. Audio produced by Michael Hanson of WHA Public AM radio, Wisconsin