Nerida Ellerton and Ken Clements, math professors at Illinois State University, recently unearthed two math book pages belonging to the 16th U.S. President, Abraham Lincoln, which prove that Lincoln spent more time at school than previously believed.

The pages found in the Harvard University archives disclose Lincoln's ability in math and prove that he was no slouch and was quite a gee whizz at numbers.

Before the professors uncovered the two pages, researchers believed that Lincoln's oldest known manuscript involved only 10 leaves. The recently found pages now represent the 11th leaf of Lincoln's workbook.

The problems and dates featured on the two pages- 1824 and 1826 - suggest that Lincoln perhaps worked on the book occasionally over a period of several years. Both the professors feel that he could have started his work as a 10-year-old boy.

"Most people say he went to school for anything between three months and nine months" over the course of his life, Clements said. "We think he went to school [for up to] two years."

Below is the list of the problems found on the recently discovered pages:

- If 100£ in 12 months gain 7£ interest what principal will gain 3£-18S-9d in 9 months?

- If the tuition of 3 boys for two quarters of a year be $40-20 cts how much will the tuition of 60 boys amount to for 4½ years?

- If 4 men in 5 days eat 7 lb. of bread, how much will be sufficient for 16 men in 15 days?

- If 100 dollars in one year gain 3½ dollars interest, what sum will gain $38.50 cents in one year and a quarter?

"The solutions to the mathematics problems in Lincoln's manuscript show that the young Abraham not only knew what he was doing, but also that he understood the mathematical principles he was applying," said Clements and Ellerton. "Almost all of his problem solutions were correct. And very little of the work is wrong."

An associated document in Houghton Library, written by William Herndon, Lincoln's law partner, certifies that both sides of the leaf were in fact prepared by a young Lincoln. He prepared his arithmetic manuscript, which was earlier known as 'cyphering book,' when attending schools in Indiana between 1820 and 1826. The Harvard University leaf was maybe completed by Lincoln when he was 16 years old, late in 1825.