''Emotional Arithmetic'' focuses primarily on three people who formed a bond in the Drancy internment camp, where they were imprisoned by the Nazism during World War II: Jakob Bronski (Sydow), who saw goodness in two orphaned children in the camp, Melanie (Sarandon) and Christopher (Byrne), and who helped them to survive. Decades after their release from Drancy, their emotional wounds still affect their lives in different ways when they meet again.