The central theme of The Devil’s Arithmetic is the importance and power of memory. At the opening of the novel, Hannah is bored and frustrated by her relatives’ constant need to remember the past; she cannot understand why her grandparent’s memories are so important to them.Then Hannah is transported to a Jewish village during World War II, where she, along with other Jews, is forced into a concentration camp.Ironically, as soon as Hannah arrives at the camp, she loses her own memory: when her head is shaved, she finds that she can no longer remember her own past in New York or the history of the Nazis. Only when Hannah is stripped of her own power to remember and forced to experience the horrifying events of the Holocaust firsthand, does she begin to understand the true power of memory.

Soon after she loses her memory, Hannah has a number tattooed on her arm by another prisoner in the camps. The tattooist tells her his own daughter—who has died in the camps—shared Hannah’s Hebrew name, Chaya. The man tells Hannah she must remember, for memories keep his daughter and all those who have died alive. Without memory, he warns, life does not exist. However, Hannah cannot truly understand his message until she experiences the horrors of the camp herself.

In the camp, Hannah befriends Rivka, who has already lost many relatives. Yet instead of letting her loss defeat her, Rivka becomes more determined to live and remember—as she says, through the memories of the living, “all those gone before are alive inside us.” When Hannah tells Rivka about her own loss of memory, Rivka says this because remembering can be so painful. However, she assures Hannah that her memory will return, as soon as she is ready for it.

Only after Hannah has learned to become a stronger, braver person—by witnessing the horrors in the camps, finding the strength to keep living, and helping others even when she has so little herself—does her memory begin to return. This time, when Hannah remembers her life in America, she recognizes the true power of her memories and shares them with others. She tells Rivka and their friends that one day there will be a Jewish state with a Jewish president, that the Jews will survive.She pleads with her friends to remember as well, to “carry the message” of survival into the future and ensure that the horrors of the Holocaust will never happen again. Finally, Hannah understands and uses the true power of memory, as painful as it may be.

Related to the theme of memory is the power of storytelling in the novel.In the opening, Hannah belittles and refuses to listen to her grandparents’ stories. However, soon after arriving in the past, even before she is taken to the concentration camps, Hannah begins to recognize the power of stories. The day after she arrives in the Jewish village, Hannah meets some of the children and tells them the plots of modern books and movies, in the form of oral stories. Hannah’s words fascinate the children, and Hannah herself is amazed “at this strange power she held in her mouth.”

Hannah draws on her newly discovered “strange power” of storytelling at the time she needs it most—when she is headed to the gas chamber.As she and two other girls walk toward their deaths, Hannah tells the girls a story about her future self: “a girl named Hannah” who lives in New York. Thus, even in her moment of darkest despair, Hannah uses a story to maintain hope for the future—in both herself and others.

Another crucial idea in the novel is the definition of true heroism. When Hannah is distraught over the death of a young child she has grown close to, she says the Jews in the camp are “monsters” to let these horrors continue without actively fighting. Rivka, on the other hand, believes that it is much more difficult to continue to live, suffer and watch others suffer than to “go out shooting"; she concludes that everyone who finds the will to continue in the camp is a hero. Later in the novel, the author illustrates the truth of Rivka’s statement: the survivors of the camp, like Gitl and Rivka, allow the memories of those who perished—including Chaya—to live on. Specifically, Gitl names her organization after Chaya, and Aunt Eva/ Rivka names her niece after Chaya as well.

The author supports this idea of true heroism in her afterword, where she re-emphasizes the importance of memory and storytelling. Yolen says that for the camp’s survivors, true heroism was simply to live, to endure, “to witness” and “to remember.” Through the novel itself, Yolen tells a story that keeps the past alive for new generations of readers; thus, the author herself continues the acts of witnessing and remembering practiced by the camp’s survivors.