"What's in a number?"

"To many, 81 percent is a success story. It's the nation's all-time-high rate for high school graduation in 2013, the most recent year of federal data."

"But the NPR Ed Team and reporters from member stations around the country have been digging into that number and found it's more complicated."

"Not all the news here is good."

"Yesterday, we took you to the state with the highest graduation rate — Iowa — to see what it's doing to keep at-risk students in school: free day care, an in-school food bank, small classes and flexible hours."