Lunch lady and the Mutant Mathletes by Jarrett J. Krosoczka. Random House, 2012.
Dee, Hector, and Terrence are assigned to the school mathlete team in lieu of detention for skipping out on the class field trip to the museum (Lunch Lady and the Field Trip Fiasco: Lunch Lady #6.) The team must compete in the Math Match Competition against the never defeated private school Willowby Academy kids who sneer at the public school teams. There is something strange about the kids on the Willowby Academy team. Lunch Lady and her trusty assistant Betty investigate and ride to the rescue wielding their high tech lunch room gadgets
Krosoczka absolutely connects with young readers through his art and his sense of humor. I personally believe his insight stems from his time working at the Hole in the Wall Gang camp. It may be a chicken and egg thing. Did he work there because of this focus or did he gain it from working there. Dunno. My niece told me that she really, REALLY liked the Babymouse books I sent her but she LOVED the Lunch Ladies.