The Devil’s Arithmetic, by Jane Yolen, 1988

Hannah’s grandfather survived the Holocaust, and she wishes he’d stop carrying on about it. During a family Seder dinner, she is transported to a Jewish settlement in Poland during World War II, hours before that shtetl is conducted to a Nazi concentration camp. A successful use of time travel brings the lessons of the Holocaust to modern readers, convincingly depicting the courage and loyalty found in the death camps, as well as the suffering endured and lives devoured. Serious and sobering in theme and content; strongly recommended for readers ready for such mature subjects.