Hyperbole is a literary tool that uses an exaggeration of an idea in order to create a larger emphasis on it for the reader. In pages 27–29 of my edition, readers see hyperbole being used when the narration is explaining about all of the things that Maniac Magee likes about his new life and new community. One example that we are given is about the Fourth of July and how much Maniac loves it. He likes it a lot because the "whole East End" shows up for the day. This is hyperbole because there is likely at least one single person that did not show up for one reason or another, but it gives the emphasis that a lot of people from that part of town showed up.
Another hyperbole from those pages tells readers that Maniac Magee scored a lot of touchdowns in their pickup football game that he was playing with Hands Down. Hands Down picks Maniac, and everybody laughs at his pick because Maniac is so young looking; however, Maniac amazes them all with his ability to run routes well and catch anything that Hands Down throws near him. By the time that dinner is called for, Maniac supposedly scored 49 touchdowns. That's just crazy. That's 294 points scored by one guy. If Maniac scored a touchdown every 10 minutes, it still would have taken him over 8 hours to score all of those points.