Updated

Kids in the U.S. are improving in reading and math, and low-achieving students are making the biggest gains.

The 2008 scores come from the National Assessment of Educational Progress, a federal test considered the benchmark of how students perform across the country.

They were released Tuesday in a report that measures reading and math scores against long-term trends.

Results were particularly noticeable on reading. In 2008, kids in every age group — 9, 13 and 17 — made gains. That hasn't happened since 1975.

In math, scores improved for younger kids, but scores for 17-year-olds remained flat.

Education Secretary Arne Duncan says it's a step in the right direction, but there is more work to be done.