Education is a human right and a key factor to reducing poverty and child labour and promoting democracy, peace, tolerance and development. Yet more than 100 million children of primary school age, the majority of them girls, are not enrolled in school. Millions more are taught by untrained and underpaid teachers in overcrowded, unhealthy and poorly equipped classrooms. And one third of all children do not complete five years of schooling, the minimum required for basic literacy.