Seven books for a unit on the ground under our feet, spread wide enough that every child in the room can read one at their own level and still be in the same lesson. There's a rock reference to browse with a hand lens, a four-minute painted read-aloud, a Step-into-Reading account of Pompeii a seven-year-old can finish alone, and an eighty-page book about the scientists who fly toward erupting volcanoes for a living. Hand each child the one that fits and keep the whole class pointed at the same question: what is the Earth actually doing under there, and how does anybody know?
This is a classroom text set: different children can be reading different ones on the same afternoon and still be studying the same thing. Pick by topic and by level. Volcanoes by Seymour Simon is the shared starting ground because it's short, enormous to look at, and pins down the vocabulary the rest of the unit leans on. From there the set forks. Rocks & Minerals and A Rock Is Lively cover the same rocks two ways, one to identify things with and one to make anybody care about them. Earthquakes takes the tectonics down to a level a five-year-old holds. Then three books answer the question of what all this is for: Island shows a volcano building a world instead of wrecking one, Pompeii shows what happened to a town that had no warning, and Eruption! follows the scientists whose job is making sure no town gets a Pompeii again. Hand each child the book that fits, and keep everyone circling the same question: what's happening under the ground, and how would we know?