Althea and her friends (Kiara, Sofia, and Aiden) begin to explore the history and ideas of calculus, with a bit of help from Mom. The schools are online because of Covid, and they're all homeschooling for the duration. They've only taken one year of algebra, so Mom brings in lots of activities that review algebra and geometry concepts.
Those activities (and more) are found in the Activity Book that accompanies the story. They're also available here, in the "course site" Mom has set up for Althea and friends.
Note on what's left out: I left out many topics that are normally included in a conventional course. I wanted the story to be short enough so that the size of the book wouldn't be intimidating (under 350 pages). Right now my current draft is too long, and I'm looking for things to cut. Here's a list of topics left out.
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