U.S. President Barack Obama shares his strawberry pie with a boy during a lunch stop at the Kozy Corners restaurant in Oak Harbor, Ohio, in this July 5, 2012 White House handout photograph obtained on March 14, 2013. Math enthusiasts celebrate March 14 nationwide as Pi day. Pi is the mathematical constant approximately equal to 3.14. Picture taken July 5, 2012. REUTERS/Pete Souza/White House/Handout (UNITED STATES - Tags: POLITICS SOCIETY TPX IMAGES OF THE DAY) ATTENTION EDITORS - THIS IMAGE WAS PROVIDED BY A THIRD PARTY. FOR EDITORIAL USE ONLY. NOT FOR SALE FOR MARKETING OR ADVERTISING CAMPAIGNS. THIS PICTURE IS DISTRIBUTED EXACTLY AS RECEIVED BY REUTERS, AS A SERVICE TO CLIENTS