Do the Math: Secrets, Lies and Algebra - Wendy Lichtman

Eighth-grader Tess is a math whiz, but other aspects of her life are challenging. She knows that there's organized cheating on a history exam, but isn't entirely sure who's involved. And her mother's suspicions about the apparent suicide of her friend's wife worry her as well. She can't understand why her mother doesn't take her suspcions to the police, so she does some investigation of her own. Meanwhile, she tries to make sense of her perplexities using concepts from algebra.