Devlin's Angle

April 2011

Finger Counting

For more superb videos from the hugely talented Vi Hart, go to

Devlin's Angle is updated at the beginning of each month. Find more columns here. Follow Keith Devlin on Twitter at @nprmathguy.  RSS 
Mathematician Keith Devlin (email: is the Executive Director of the Human-Sciences and Technologies Advanced Research Institute (H-STAR) at Stanford University and The Math Guy on NPR's Weekend Edition. His most recent book is Mathematics Education for a New Era: Video Games as a Medium for Learning, published by AK Peters/CRC Press.