There are 65 million grandparents in the nation, and 10 percent (nearly 7 million) of those grandparents live with at least one grandchild. The latest U.S. Census figures, compiled in a study titled Coresident Grandparents and Their Grandchildren: 2012, confirms these numbers. That said, elderly grandparents and young relatives don't necessarily happily share meals at dinner time, because that isn't the reality of today's multigenerational household.