Seven books for an inventors unit. A child who needs a picture book about a girl who builds a flying machine out of cheese-can parts is doing the same unit as the child three seats over who's 200 pages into a Malawian teenager building a windmill during a famine. Six real inventors and one glorious 400-page reference on how the made world actually works, so you can hand each child the book they can read and still keep the whole room pointed at one question.
Five different children can be reading five different books on Tuesday and still be in the same lesson, which is the whole point. Two kinds of book sit side by side on purpose. Four are biographies of real inventors, and they're about people: what they noticed, what they were told they couldn't do, how long it took. One is a reference, David Macaulay's great fat illustrated encyclopedia, which nobody reads front to back and everyone reads forever. Girls Think of Everything sits between the two, short profiles a child can graze. Rosie Revere is the only invented story in the set and the only place to start if you want one, because it makes failure funny before anyone's asked to admire it. A word on truth-telling, since these are real people: invention stories get tidied up for children more than almost any other kind of history. Whole books get titled after claims the record doesn't quite support. Rather than paper over that, put it to work, because 'who really invented this, and who says so?' is a better question than anything else this unit could ask.