LOS ANGELES, DEC. 20 -- A Los Angeles teacher who has enjoyed unusual success teaching calculus at a high school for disadvantaged students has escaped a threatened transfer for allegedly demeaning minorities.

Jim Horsman said he had instead been reprimanded for using insensitive language and had promised to be more careful in what he said in class. One student alleged that Horsman had told a class "the reason blacks don't get ahead is that they are all ignorant." Horsman denied the charge.

Horsman's case illustrated tension in Los Angeles and other big-city school systems between teachers and administrators who heavily emphasize academic achievement and an equally large number of educators who fear the push for higher scores will harm the self-esteem of weaker students. In May, 17 of Horsman's high school students passed the difficult Advanced Placement calculus test for college credit. Horsman's background as an "emergency credential" teacher, one of thousands hired nationwide with little teacher training but solid academic skills, also fueled the controversy.

Horsman said Manual Arts High School Principal Marv Starer gave him a three-page letter that said students reported "racial comments" that some of them "don't take . . . seriously or personally." In the letter, Starer directed Horsman "to be vigilant in guarding against the use of any language or commentary that may be perceived as inappropriate or insensitive to any racial and/or ethnic group."

In an earlier interview, Starer said he was concerned about anything that might create misunderstanding among the predominantly Hispanic and black students at the school in a low-income, gang-ridden area of south-central Los Angeles.

Parents of some students and some faculty members have complained bitterly about Horsman's methods, which sometimes have included harsh challenges to students who are performing poorly. Joshua Pechthalt, a social studies teacher and union leader at the school, had predicted Horsman would be treated leniently "in part because of the fact our district is racist."

But Horsman was backed by the director of the school's growing Advanced Placement program and Starer received several letters from students, including blacks and Hispanics, praising Horsman's methods.