Children in East Asian countries continue to do better than their peers around the world in mathematics, according to a report.
Northern Ireland comes just behind the top five - Singapore, Hong Kong, Korea, Chinese Taipei and Japan - where students aged around 10 years old continue to outperform all participating countries in maths.
This maintains a 20-year edge, according to results released from TIMSS - the longest-running large-scale international assessment of mathematics and science education in the world at the International Study Centre at Boston College.
Between the top-performing countries and the next highest performer - Northern Ireland - there is a gap of 23 points.
Singapore is on 618 points, Hong Kong on 615 points, Korea on 608 points, Chinese Taipei on 597 points, Japan on 593 points, while Northern Ireland is next on 570 points.
England is on 546 points and Ireland is on 547 points.
Northern Ireland and England showed the same average achievement from 2011 to 2015.
An average of 36% of students hit the high benchmark of 550 in which students are said to be able to apply knowledge and understanding to solve problems.
The East Asian countries were strong in science as well, but the results were more varied.
In fourth grade (where children are aged around 10) science, Singapore, Korea, Japan and the Russian Federation had the highest achievement, and in eighth grade (where children are aged around 14) science it was Singapore, Japan, Chinese Taipei, Korea and Slovenia.