In the novel, Rivka teaches the other girls her number and shows them how to create a method for remembering their own. Her number is J18202 which she explains she remembers as an important piece of information to keep. The J stands for Jew like the rest of the girls, 1 stands for the fact that she is all alone in the camp, the 8 stands for the whole family she had before the camp, the two is for the two who are left meaning herself and her brother Wolfe. The 0 stands for Wolfe who thinks he is worth nothing while the last 2 stands for the two who will be together from her family when this is all over. Rivka gives the girls a device to remember their number, but also teaches them how important it is to remember the people who live and die in the camp. The world must be made to remember to prevent this ever happening again.