WASHINGTON -- The Bethesda-Chevy Chase (Md.) High School team was on a roll in the first round of the Saturday morning television quiz competition "It's Academic."

Although they won that day last winter, the Bethesda-Chevy Chase scholars had an embarrassing moment when host Mac McGarry asked what seemed like a fourth-grade question: "How much is a 4 percent sales tax if the purchase price is $90?"

There was an awkward silence, and as time ran out, team captain Ann Horwitz made a guess: "$3.50?"

Close, but no points -- another sign of American students' problems with practical arithmetic, which many educators say is vital for daily life as well as school. And now a Brookings Institution researcher is saying that computation test scores are stagnating or declining in the United States and the government has covered it up.

In a report released Tuesday, Tom Loveless, director of the Brown Center on Education Policy at Brookings, said the federally funded National Assessment of Educational Progress has presented a cheery picture of math scores in the last decade, even as scores have languished.

In his report, Loveless, a former teacher and Harvard professor, laments a decision by the board that oversees NAEP. The decision relegated the test of students' basic math skills without the aid of calculators -- derided by some experts as "shopkeeper arithmetic" -- to a part of a larger test. As a result, the computation scores are not reported separately.

Larry Feinberg, spokesman for the National Assessment Governing Board, which oversees the $111-million-a-year testing system, said Loveless' analysis of NAEP data was "selective and distorted." He said Loveless excluded some percentage questions that would have shown arithmetic achievement unchanged for 17-year-olds and improving for 13-year-olds during the 1990s.

Loveless, in response, said that however the scores are presented, they are too low.