The last 15 years have seen major changes to education systems in East Africa. Superficially, there is much to commend. Net primary enrolment rates have risen to over 90% alongside significant improvements in gender equity. Nonetheless, there are growing concerns that better access is not adding up to more learning. This paper introduces unique test score data collected by Twaweza's Uwezo initiative for over 600,000 children across East Africa, including children enrolled and not enrolled in school. Using these data we show that many children in Kenya, Tanzania and Uganda remain functionally illiterate or innumerate, despite having completed multiple years of school.