For many people in Latin America, education is unaffordable. In Colombia, nearly three million children don't attend school. Children from poor families are often excluded from good schooling. That's where Marta Arango's work kicks in. Her organization supports schools with teaching materials and educates teachers. Teenagers and young adults are incorporated into her work.The Colombian social entrepreneur's organization, the International Center for Education and Human Development, has its headquarters in the former drug stronghold of Medellín. Arango began working to provide access to education for fellow Colombians more than thirty years ago.