Of the world's 650 million primary school age children, at least 250 million are unable to read, write or do basic mathematics, according to a report commissioned by the U.N. education agency on Wednesday.
The report found that 130 million are in primary school but have not achieved the minimum benchmarks for learning, and almost 120 million have spent little or no time in a classroom including 57 million youngsters who are not attending school, the Associated Press reported.
The cost of 250 million children around the world not learning translates to a loss for governments of around $129 billion annually, the independent research team that wrote the report for UNESCO, the U.N. Educational, Scientific and Cultural Organization, calculated.
This global "learning crisis" is mainly caused by a lack of well-trained teachers, especially in impoverished areas, Vibeke Jensen, UNESCO's U.N. representative, said.
"While more children are in school, it's been at the cost of quality," she said at a news conference launching the report. "The issue now is to put the focus on quality."
According to the AP, in a third of countries analyzed by the team, less than 75 percent of the primary school teachers had been trained to meet national standards.
"Teachers have the future of this generation in their hands," UNESCO's Director-General Irina Bokova said in a statement. "We need 5.2 million teachers to be recruited by 2015, and we need to work harder to support them in providing children with their right to a universal, free and quality education."
A country's gross domestic product per capita can be increased by 23 percent over 40 years through ensuring an equal, quality education, the report said.
"But according to the report, almost half the children out of school globally are expected never to make it into a classroom - and that includes almost two-thirds of girls in Arab states and sub-Saharan Africa," the AP reported. "The research team reported that almost half the world's out-of-school population of 57 million live in conflict-affected areas, up from 42 percent in 2008."
In 2011, it estimated that 14 countries had more than one million children out of school. This included Afghanistan, China, Congo, Somalia, Sudan before its break-up, and Tanzania, the AP reported.
On the other hand, Laos, Rwanda and Vietnam are the three countries that have reduced their out-of-school populations by at least 85 percent in the last five years, the report said.
World leaders set a goal in 2000 of giving every child a primary school education by 2015 but the report said it is "likely to be missed by a wide margin."
According to the AP, the region that is lagging farthest behind is Sub-Saharan Africa.
The researchers forecast that if recent trends in the region continue, the richest boys will achieve the goal of completing primary education in 2021 but the poorest girls will not catch up until 2086, the AP reported.
