LOS ANGELES — Students and parents may complain often and loudly about the homework load these days, saying it has created a stressed-out generation. But a new report contends that is not so and that many students actually don’t do enough – or challenging enough – math and reading.

“If students are going to succeed in the competitive global economy, they need to be exposed to a rigorous curriculum. But many students believe their classwork is too easy,” said the study by the Center for American Progress, a liberal-leaning think tank in Washington.

The report – “Do Schools Challenge Our Students?” – analyzed national and state-by-state results of federal student surveys about the rigors of school and homework assignments in elementary, middle and high schools.

According to the study, 37 percent of fourth-graders across the country say their math work is often or always too easy. Among eighth-graders, 29 percent nationally report such frequent and simple assignments. Almost a third of middle schoolers in the U.S. say they read less than five pages a day at home or at school, and more than half say they read no more than 10 pages.

The report’s authors, Ulrich Boser and Lindsay Rosenthal, also say there is a learning gap, with lower-income students falling behind and “less likely to have the same access to robust learning opportunities.”

The surveys show that 74 percent of higher-income fourth-grade students report that they often or always understand what their science teacher is saying, compared with just 56 percent of lower-income fourth-grade students. Among middle-schoolers, 80 percent of higher-income students report often or always understanding what math teachers ask compared with 70 percent of lower-income students.

“Over the past few years, many states have engaged in promising reforms that address the issues raised by this report. But our findings suggest we need to do far more to improve the learning experience for all students,” Boser said in a statement.