[bityard]

I'm reading it to my nine year-old, a chapter at a time. He is likely technically capable of reading it himself but he doesn't have the focus to get through more than a page or two on his own. But he likes spending time with me no matter what we're doing and he is having no problem understanding the concepts in the first few chapters so far. He particularly loves (re-)inventing practical applications for the concepts being introduced, like the flashlight telegraph.