BLOOMINGTON -- If the discovery of some teenager's math calculations written out nearly 200 years ago doesn't seem too exciting, consider the student: Abraham Lincoln.
The (Bloomington) Pantagraph reports that a page from what was called a ciphering book belonging to the 16-year-old Lincoln was recently determined to have been a missing "leaf" from his workbook
The leaf was discovered in 2009 by two Illinois State University mathematics professors -- Nerida Ellerton and her husband Ken Clements -- at Harvard University's Houghton Library. But only recently did they learn it was once part of a workbook of Lincoln's from the 1820s.
The two math professors not only found the 11th leaf scholars know about from same workbook, but they checked Lincoln's work and determined he didn't make any mistakes.