"We have succeeded in reducing the drop-out rate to insignificant levels, " said Senhora Zimmerman, 56, head of the Anne Frank Municipal School. This year, she said, none of the students at the 700-pupil school abandoned classes, compared to the 25 per cent who dropped out last year.
"Getting children to stay at school is the first task we have to undertake if we want to reduce high illiteracy rates in our country," she said. "The main reason for school evasion and low educational levels in Brazil is that children are forced to go out to work to boost their families' meager incomes."
Her school was one of the first to benefit from a government plan to pay poorer parents who send their children to school. She said: "They receive the equivalent of one minimum salary per month, (US $120, Pounds 76) per child, who attends school.
"We cannot question the morality or foresight of parents who force their children to help with income. Poverty gives them no choice. Most of them have also never had the benefit of an education themselves."
The government has just announced plans to use US $500 million (Pounds 317 million) from privatisations to widen the programme. State-provided education has not been a priority for successive governments, and 60 per cent illiteracy among the 80 million "underclass" has increased the gap between rich and poor.
The realisation that Brazil lags behind most of its South American neighbours and is hard-pushed to provide a skilled labour force, even though it is the continent's biggest economy, has triggered action.
The "battle" is far from won for the head who supplements a US $1,000 (Pounds 635) monthly income by giving night classes to trainee teachers at a local university. "Incomes are so low that many teachers have to take up various jobs to make ends meet, and many don't turn up but take home salaries anyway, " said Mary Zimmerman. An average teacher's salary is US $500 a month.
The authorities claim there are enough school places to cater for Rio's 400,000 children and more than sufficient registered teachers. But a recent survey showed that at least 25,000 teachers were taking home a salary although they were not attending lessons.