CAMBRIDGE – Sometimes it takes a parent, sometimes it takes a teacher. But if you really want to get some kids’ attention, call a cheerleader. Better yet, call all 21 of them. The entire Cambridge-South Dorchester Viking cheerleading squad turned out for Choptank Elementary School’s pep rally on Friday. The children were lined up by classes, sitting on the gym floor, where they heard a few words from first-year, fourth-grade teacher Brianna Opher. “The reason we have this assembly every year is to remind you of the four Rs,” she said. The four Rs – Responsible, Respectful, Resilient and Ready to Learn – are part of the school’s PBIS plan. “PBIS is Positive Behavior Interventions and Supports, a proactive approach to establishing the behavioral supports and social culture needed for all students in a school to achieve social, emotional and academic success,” a written statement from Choptank Social Worker Kawana Webb said. Students applauded the remarks of some of their classmates, who shared their thoughts on the importance of the four Rs. Some won prizes when drawings named their birthdays, and the children competed by class to see who could cheer the loudest. But maybe the loudest applause came when the Viking cheerleaders were introduced and the girls ran into the gym. They performed routines, and the seniors among them introduced themselves and told the children – many of whom were wide-eyed and enraptured by the glamorous high school girls – that they were on their way to college after graduation. The event ended with a quick dance party before the Hummingbirds thanked their visitors and returned to their classes.