What was Pete's great idea in Frindle?
The answer to this question can be found in chapter 8. At this point in the story, Nick, the protagonist, is engaged in what from his perspective is a "war" with one of his teachers, Mrs. Granger. At this stage in the "war," Mrs. Granger is winning, and Nick's reputation as "the teacher-stopper" is under threat.
Nick's friend, Pete, comes up with his "great idea" while walking to school. He proposes that he and Nick, and another friend called Dave, should try to "get every kid in the whole fifth grade to go up and ask Mrs. Granger, 'Can I borrow a frindle?'" This is the word Nick has been using instead of pen, in a deliberate attempt to antagonize Mrs. Granger. Mrs. Granger, earlier in chapter 8, has kept Nick behind after school to talk to him about his use of this new word.
Nick thinks that Pete's idea is "great" firstly because he reasons that Mrs. Granger "can't keep everyone after school" and secondly because he thinks it might help to reaffirm his proud reputation as "the teacher-stopper." Later that day, after school, "almost eighty kids" stay behind with Mrs. Granger for asking for a frindle.
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