Schooling without learning
New hard-hitting report released by the United Nations shows that out of every 10 children and teenagers in the world six are failing to reach basic levels of proficiency in learning.
Narrowing it down to the sub-Saharan African region, the learning crisis is very damning.
The research suggests that in the sub-Saharan Africa region 88% of children and adolescents enter adulthood without a basic proficiency in reading.
Over the period international aid in education has focused on the lack of access to schools, particularly in poorer countries in sub-Saharan Africa or in conflict zones rather than the learning crisis.
This development has made the new research by Unesco Institute for Statistics warn of the lack of quality within schools.
According to the report, more than 600 million school-age children do not have basic skills in maths and reading.
In North America and Europe, only 14% of young people leave education at such a low level.
The research states that only 10% of the world's school-age children live in these more affluent, developed regions.
Silvia Montoya, director of the Unesco Institute for Statistics says "many of these children are not hidden or isolated from their governments and communities - they are sitting in classrooms".
Pupils in Kenya, Tanzania, Uganda and Nicaragua are unable to do simple sums or read simple sentences even after years in school.
Only 7% of pupils in Mali have a basic level of proficiency in primary school.
There are also wide gulfs within countries. At the end of primary school in Cameroon, only 5% of girls from the poorest families were at a level to continue with their education, compared with 76% of girls from wealthy families, the report said.
The World Bank study examined the factors underlying such poor achievement:
It warned that in the poorest countries many pupils arrived at school in no condition to learn
Many had suffered from malnutrition and ill health, the World Bank said, and the deprivation and poverty of their home lives could mean they began school physically and mentally underdeveloped
There were also concerns about the quality of teaching, with too many teachers not being particularly well educated themselves
There was also a problem of teacher absenteeism in some countries in sub-Saharan Africa, which has been linked to teachers not being regularly paid