Two Australian mathematicians assert that an ancient clay tablet was a tool for working out trigonometry problems, possibly adding to the many techniques that Babylonian mathematicians had mastered. It's a trigonometric table, which is 3,000 years ahead of its time," said Daniel F. Mansfield of the University of New South Wales. Dr. Mansfield and his colleague Norman J. Wildberger reported their findings last week in the journal Historia Mathematica. The tablet, known as Plimpton 322, was discovered in the early 1900s in southern Iraq and ... contains 60 numbers organized into 15 rows and four columns. With all the publicity, the tablet has been put on display at [Columbia] University's Rare Book & Manuscript Library. Plimpton 322 has been dated to between 1822 and 1762 B.C. One of the columns on Plimpton 322 is just a numbering of the rows from 1 to 15. The other three columns are ... Pythagorean triples - sets of integers, or whole numbers, that satisfy the equation a2 + b2 = c2. That by itself was remarkable given that the Greek mathematician Pythagoras, for whom the triples were named, would not be born for another thousand years. "You don't make a trigonometric table by accident," Dr. Mansfield said. "Just having a list of Pythagorean triples doesn't help you much. That's just a list of numbers. But when you arrange it in such a way so that you can use any known ratio of a triangle to find the other sides of a triangle, then it becomes trigonometry. That's what we can use this fragment for."