What is the most significant passage in the book The Devil's Arithmetic?

A significant passage in The Devil’s Arithmetic is when Hannah is getting her head shaved, because that is when she realizes that memories are important.

At the beginning of the book, Hannah is complaining because all Jewish holidays seem to be about remembering.  She does not understand why she has to remember so much.  She can’t empathize with her relatives, who are still bitter and broken from their experiences in the war.  The war is distant for Hannah.  She does not see it as something that happened to her family or her people.

Yet when Hannah is magically transported back to the Holocaust, she wants to remember.  She is beginning to forget.  She does not remember what happens next.  She does not remember who she is.  As she fails to remember, she starts to panic. 

The passage in chapter 11 where Hannah gets her head shaved is a good example of how the full reality of the situation has hit her, and how memory has become important.

…I cannot remember, she whispered to herself. I cannot remember. She's been shorn of memory as brutally as she'd been shorn of her hair, without permission, without reason...Gone, all gone, she thought again wildly, no longer even sure what was gone, what she was mourning. (Ch 11, p. 94)

This passage, which begins with, “The barber was clearly a prisoner,” and ends with, “Without their hair, all the women looked the same,” is the important one.  This passage hits hard on one of the novel’s main themes: Our collective past makes us who we are.  Hannah’s relative past was her past.  She saw that then.  She realized that this past was part of her identity.  It was part of her DNA, and part of her upbringing.

Hannah also really develops as a character through this experience.  She alone knows the full weight and history of the Holocaust.  She knows about the mass extermination of Jews, and fears that she will become one of the casualties.  Yet she remains strong, demonstrating a fundamental truth of human nature: We all want to survive. 

Hannah does survive, but she also learns that she can sacrifice herself, and be noble, if she has to.