Who are the people who get bad grades because of Nora's poor school performance in The Report Card by Andrew Clements?

In chapter 21 of Andrew Clements's The Report Card, we learn, in the words of Mrs. Hackney, the school principal, that "half of the fifth-grade class decided to treat two quizzes as if they did not matter at all" (113). As Mrs. Noyes explains in a meeting in the principal's office, on that day she handed out two quizzes on the assigned reading in their social studies textbook; she handed one to the first half of the Blue Team during the third-period class and the other to the second half of the Blue Team during the fourth-period class. In both classes, all but two students wrote nonsense answers for the questions, which earned zeroes for all but a total of four students on half of the Blue Team; therefore, we know that half of the fifth-grade class, except for four students, intentionally earned zeroes that day.

The event occurred because Nora's initial plan was failing. Her initial plan was to earn Ds as part of a plot to show that grades are not a true reflection of intelligence and, therefore, not worth the amount of pressure placed on students. Nora's plan goes off track the moment her IQ score reveals her true genius before she's ready for anyone to know. When her friend Stephen finds out about her plan and how it messed up, he helps her think of a new plan. Instead of just Nora earning bad grades on purpose to protest against the reliance on grades, Stephen and Nora encourage all the students in their class to earn bad grades. In Nora's mind, earning zeroes on tests would show the tests' true educational value. She argues that since the tests do not help students think, just memorize, the tests are worth zeroes. Stephen sets the plan in motion by phoning all fifth graders and telling them to get zeroes and by passing out flyers encouraging them to get zeroes.