Hannah is an ordinary 13-year-old girl who is self-absorbed, whiney about her family and their crazy traditions, and bitter because she wants her braces off and new clothes in her closet. She's also Jewish, and it is during a Passover seder with her family that something very strange occurs.
Hannah is mysteriously transported back to 1940's Poland, and is part of a Jewish community that is being "resettled" by the government. She experiences being crammed in boxcars like animals, along with being beaten, starved, robbed, stripped, and humiliated. While in the concentration camp, she comes to survive by attempting only to stay alive for one more minute, one more day. She feels the pain and insanity of losing people she loves one by one, constantly being treated like the scum of the earth.
The title, The Devil's Arithmetic, comes from the theme of numbers within the story. Interpreting people's tattooed numbers on their arms comes to mean the difference between life and death at times. Hannah and her remaining friends and family live each day hoping and praying that they are one less to go in the ovens, and one more to get their bowl of watery potato soup that day. This constant referral to numbers, (and the knowledge that there is no sense in seeking reason in the way things are), is where the term "the devil's arithmetic" surfaces.
I've read some pretty good pieces of historical fiction about the Holocaust, and I've explored it from several different angles. This book, though, takes the prize. It is one of the most moving works of literature I've ever had the pleasure to read.