Many teachers have such a wide range of student ability in their classrooms that they often grapple with a five to six-year difference between their most advanced and least advanced students particularly in maths, a new report reveals.

The report by public policy think-tank the Grattan Institute says extensive research shows that achievement levels in a single year can be so vastly spread that in the case of maths, many students have lagged behind their peers for several years by the time they reach secondary school.

Most teachers have a wide range of student ability in their classrooms. Credit:Photo: Quentin Jones

"Australian research shows that achievement can be spread over five to eight year levels within a single class: a year 7 class may have students working at a year 1 level, while others have mastered concepts from year 8," the report says.

"The typical year 8 maths teacher must target his teaching in a way that meets the needs of students at eight different levels of conceptual mathematical understanding, while still addressing curriculum requirements. This is no easy task."