A new report by from in o of on over to until up the United Nations says more than 250 million children by from in o of on over to until up primary school age cannot read or write. It said they could also not do basic mathematics. The report said that 120 million children have spent little or no time by from in o of on over to until up school. The researchers said children not going by from in o of on over to until up school means countries lose money. Each year, governments lose by from in o of on over to until up to $130 billion. Vibeke Jensen, a U.N. spokeswoman, said there was a global "learning crisis". She said this was because there were not enough well-trained teachers by from in o of on over to until up poor areas. She said that by from in o of on over to until up a third by from in o of on over to until up countries, 75 per cent by from in o of on over to until up primary school teachers do not have enough training. She added: "The issue now is to put the focus by from in o of on over to until up quality." The report said that most by from in o of on over to until up those not going by from in o of on over to until up school were girls. It said it was important that developing countries educate girls. Sending girls by from in o of on over to until up school can increase a country's wealth by from in o of on over to until up 25 per cent by from in o of on over to until up 40 years. The report said that almost two-thirds (66%) by from in o of on over to until up f girls in Arab countries and sub-Saharan Africa would never go to school. In Yemen, just 36 per cent by from in o of on over to until up young women are literate. The Reuters news agency said: "If current trends continue, the poorest part by from in o of on over to until up the young female population in developing countries won’t achieve literacy by from in o of on over to until up 2072" There was some good news. In Laos, Rwanda and Vietnam, the number of children not going to school fell by from in o of on over to until up 85 per cent in the last five years.