Girls and boys start grade school with different approaches to arithmetic problems - girls favour a slow and accurate approach and boys a faster but more error-prone approach.

The girls' approach gives them an early advantage, but by the end of the sixth grade, boys had surpassed the girls, a study by the University of Missouri says.

The study found that boys showed more preference for solving arithmetic problems by reciting an answer from memory, whereas girls were more likely to compute the answer by counting.

Understanding these results may help teachers and parents guide students better, says Journal of Experimental Child Psychology.

"The observed difference in arithmetic accuracy between the sexes may arise from a the willingness to risk being wrong by answering from memory before one is sure of the correct answer," said Drew Bailey, study author and a recent recipient of a Ph.D. in psychological science from University of Missouri, according to a Missouri statement.

"In our study, we found that boys were more likely to call out answers than girls, even though they were less accurate early in school. Over time, though, this practice at remembering answers may have allowed boys to surpass girls in accuracy," Bailey added.

The study followed approximately 300 children as they progressed from first to sixth grade. In the first and second grades, the boys' tendency to give an answer quickly led to more answers in total, but also more wrong answers.

Girls, on the other hand, were right more often, but responded more slowly and to fewer questions. By sixth grade, the boys were answering more problems and getting more correct.

"Developing mathematical skill may be part 'practice makes perfect' and part 'perfect makes practice,'" Bailey said.

"Attempting more answers from memory gives risk-takers more practice, which may eventually lead to improvements in accuracy. It also is possible that children who are skilled at certain strategies are more likely to use them and therefore acquire more practice."