Facebook CEO Mark Zuckerberg donates $120 million

"Education is incredibly expensive and this is a drop in the bucket."

Facebook CEO Mark Zuckerberg and his wife, Priscilla Chan, are donating $120 million to the San Francisco Bay Area's public school system.

The couple's gift will be spread over the next five years and is the biggest allocation to date of the $1.1 billion in Facebook stock the couple pledged last year to the nonprofit Silicon Valley Community Foundation.