Add Yahoo as a preferred source to see more of our stories on Google. Math students everywhere will be eating pies in class this week in celebration of what is known as Pi Day, the 14th day of the 3rd ...

When π is written in decimal notation, it begins 3.14, suggesting the date 3/14. In fact, the decimal expansion of π begins 3.1415, so Pi Day 2015, whose date was abbreviated as 3/14/15, was said to ...