The children in this study were four boys and one girl aged 9-15 years with a mean age of 11.2 and ranging in level of schooling from first to eighth grade, One of them had only one of schooling; two had three years of schooling; one, four years; and one, eight years, All were from very poor backgrounds. Four of the subjects were attending school at the time and one had been out of school for two years. Four of these subjects had received formal instruction on mathematical operations and word problems. The subject who attended first grade and dropped out of school was unlikely to have learned multiplication and division in school since these operations are usually initiated in second or third grade in public schools in Recife.