A math teacher at Lowell High School was placed on indefinite leave Monday after complaints surfaced about algebra quiz questions that referenced a girl’s weight and a “fat kid,” according to local reports.

Tom Chan, who has taught at the school for more than 20 years, assigned a quiz with word problems that included jokes about dating costs tied to a woman’s weight, the San Francisco Chronicle reported.

The controversy prompted school officials within the San Francisco Unified School District to begin reviewing the material.

Principal Jan Bautista notified parents on Monday that Chan “needed” to go on leave, but did not explain the reason for the action or how long the leave would last. The notification reportedly came shortly after the Chronicle contacted district officials about the quiz.

According to questions cited in the report, one prompt stated: “The amount of money you spend on a date varies inversely to how much they weigh,” before providing an example that a 120-pound woman would cost $55 on a date. Students were then asked to calculate the cost of a date with a 220-pound woman named Ashley and determine how much a date could weigh if someone could only afford $5.

Another section of the quiz was reportedly titled “Mr. Chan vs. The Fat Kid (part 2).” In the prompt, Chan allegedly wrote that he “punted” a “fat kid” who complained about the candy he was eating. Students were asked to solve math problems involving height and time based on the scenario and to answer a question about the last time they “gave candy to a fat kid.”

Laura Dudnick, communications director for the school district, told SFGATE that officials are aware of the complaints and have opened an investigation.

“We take these concerns seriously and are actively investigating,” Dudnick said in a statement, adding that the district could not comment further on a personnel matter.

Some parents told the Chronicle they were hesitant to report the quiz out of concern their children might face retaliation in class.

Additional scrutiny has also focused on extra credit assignments Chan reportedly offered students. According to NBC Bay Area, Chan encouraged students to perform dance routines for extra credit, posting the videos online under the title “Grades or Dignity.”

Despite the controversy, some former students said Chan was popular and helped them understand difficult material. One former student told NBC Bay Area that Chan often used humor or unusual examples to keep students engaged during lessons.

The school district has not said when the investigation will be completed or whether further disciplinary action could follow.