Even though about 70 percent of high school graduates now go on to continue their educations, fewer than half of students have taken the rigorous courses expected by colleges and employers, according to a report released yesterday by a national education group.

Comparing state graduation requirements with college admissions standards and placement exams, the Education Trust found a mismatch between what high school students are taught and what they are expected to know in order to perform in college and on the job.

About 47 percent of graduates have taken college prep courses such as intermediate algebra, said the study, a figure that sinks to 43 percent for African Americans, 35 percent for Hispanics and 28 percent for low-income students. Meanwhile, the overall percentage of graduates going to college or trade school has soared to 72 percent and, according to the report, will reach 80 percent by the time today's sixth-graders finish high school.

One result of the gap between preparation and expectations is that nearly a third of college students have needed at least one remedial course in college, said the Education Trust, a nonprofit that focuses on raising achievement levels among minority and low-income groups. The report cited a Washington Post article about the heavy demand for remedial courses at Montgomery Community College as evidence that the problem of inadequate preparation for college is not confined to urban districts.

"Many of the kids who land in remedial courses are the kids who played by what they were told were the rules in high school. They completed the courses, they passed the tests, they got admitted to college," said Janis Somerville, director of the National Association of System Heads, which represents state college leaders.

The Education Trust said mathematics was a prime example of this pattern. Most colleges expect entering students to have mastered at least intermediate algebra, a course commonly called Algebra 2. "But most states don't require students to complete even elementary algebra to graduate from high school," according to the study. Only 13 states, including Maryland and Virginia, require both algebra and geometry for graduation. The District's graduation requirements were not examined.

Matching state graduation requirements and state college admission standards revealed that in 17 of 28 states where comparisons were possible, students could earn a diploma by taking fewer math courses than colleges require for admission.

The Education Trust also evaluated a sampling of standardized tests given to high school students and found that most, including the Scholastic Assessment Test, do not demand the skills of Algebra 2. But Algebra 2 does show up on exams that many colleges use to place freshmen in math courses.

A review of a dozen standardized tests of English skills found a similar disconnect. High school achievement tests generally featured "short narratives and general interest informational pieces," the study said. College admissions and placement tests, by contrast, "were primarily academic and literary in nature."

"In our view, closing the achievement gap depends on educating all students as if they were bound for college and the workplace," wrote Education Trust Director Kati Haycock in the report's introduction.