PARIS -- Students from the Chinese mainland scored the highest level in reading, science, and mathematics in the latest PISA global education test hosted by the Organization for Economic Cooperation and Development (OECD), results released on Tuesday showed.

They are followed by students from Singapore and China's two special administrative regions -- Macao and Hong Kong. The top OECD countries were Estonia, Canada, Finland, and Ireland.

The OECD's PISA 2018 tested around 600,000 15-year-old students in 79 countries and economies on reading, science, and mathematics. The main focus was on reading, with most students doing the test on computers.

Students from Beijing, Shanghai, provinces of Jiangsu and Zhejiang, represented the Chinese mainland in this test. In reading, they scored significantly higher than their peers from other countries.

"Most countries, particularly in the developed world, have seen little improvement in their performances over the past decade, even though spending on schooling increased by 15 percent over the same period," said the OECD when releasing the results.

"One in four students in OECD countries are unable to complete even the most basic reading tasks, meaning they are likely to struggle to find their way through life in an increasingly volatile, digital world," it added.

In science and maths, around one in four students in OECD countries, on average, do not attain the basic level of science (22 percent) or maths (24 percent). That means they cannot, for example, convert a price into a different currency.

About one in six students (16.5 percent) in China's Beijing, Shanghai, Jiangsu and Zhejiang, and one in seven in Singapore (13.8 percent), perform at the highest level in maths, compared to only 2.4 percent in OECD countries.

As to equity in education, students performed better than the OECD average in 11 countries and economies, including Australia, Canada, Denmark, Estonia, Finland, Japan, South Korea, Norway, and the United Kingdom, while the relationship between reading performance and socio-economic status was weakest.

"This means that these countries have the most equitable systems where students can flourish, regardless of their background," said the OECD.

The test found that girls significantly outperformed boys in reading on average across OECD countries, by the equivalent of nearly a year of schooling.

Across the world, the narrowest gaps were in Argentina, the Chinese mainland, Chile, Colombia, Costa Rica, Mexico, Panama, and Peru. Boys overall did slightly better than girls in maths but less well in science.