The circumference of a circle is the distance around the shape. The ability to round a number to a number of decimal places or to a number of significant figures means that answers can be written to ...

So you have a circle. What is the area of that circle? Surely everyone remembers that the area of a circle is: Where Pi (π) is of course the number and r is the radius of the circle. Where does this ...

One of my favorite holidays is Pi Day. On March 14, people who love the math constant called pi celebrate by eating the other kind of pie. Like apple pie, pumpkin pie and even pizza pie. I talked ...

Editor's note: A version of this story was published in March 2011. Get ready to roll out some dough, because it's almost Pi Day. What's that, you ask? Think back to geometry class. Pi represents the ...

Beth Py-Lieberman - Author, The Object at Hand: Intriguing and Inspiring Stories from the Smithsonian Collections Every year, the celebration of Pi Day (March 14 is 3.14) grows more ambitious. Math ...