Hong Kong school students, along with their Asian peers, continued to outperform their Western counterparts in the latest international mathematics assessments. The city's primary school pupils were among the top three in the tests, taken last year and gauging 63 countries and regions, while its secondary pupils were in the top four. But they did not score as highly in corresponding science tests, ranking eighth for secondary and ninth for primary. Local primary pupils, meanwhile, were named among the four top performers in literacy in another world ranking organised by the International Association for the Evaluation of Educational Achievements. The tests are taken every five years. In the last tests, in 2006, the city's primary pupils came first in mathematics. The results from Asian countries were described as "rather breathtaking" by an American professor involved in the tests. The Hong Kong tests were administered by the University of Hong Kong education faculty. The faculty said nearly 4,000 primary four pupils from 136 schools and a similar number of Form Two pupils from 117 secondary schools took the maths and science test, while the reading assessments were given to 4,200 primary four pupils. On a 1,000-point scale, primary pupils scored on average 602 in mathematics - three and four points short respectively of runner-up South Korea and champion Singapore. Students from the United States scored 541. In the secondary category, the SAR pupils came in behind South Korea, Singapore and Taiwan. Ina Mullis, an education professor at Boston College involved in the administration of the tests, said: "The dramatically superior achievement of the Asian countries is rather breathtaking." But Tom Loveless, a senior fellow at the Brookings Institution who in previous years represented the US in the international group that administers the tests, said: "These kinds of tests are very good at telling us who's ahead in the race. "They don't have a lot to say about causes or why countries are where they are." In the reading exam, Progress in International Reading Literacy Study, Hong Kong, Singapore, Russia and Finland were categorised as the top performing jurisdictions. The tests were taken by 300,000 children from 49 countries.