Quote 7
"But does it not intrigue you," Miss Honey said, "that a little five-year-old child is reading long adult novels by Dickens and Hemingway? Doesn't that make you jump up and down with excitement?" (9.39)
In this moment, Miss Honey is the voice of reason. She's the one who is making sense. She's correct that if someone Matilda's age is doing such advanced things as reading Dickens and Hemingway, people should be amazed and excited. If Mr. and Mrs. Wormwood aren't excited, that shows they're the ones who are messed up, not Matilda.
Quote 8
"A precocious child," Miss Honey said, "is one that shows amazing intelligence early on. You are an unbelievably precocious child."
"Am I really?" Matilda asked. (16.19-20)
Just in case we were tempted to be jealous of our Matilda, here we get a reminder that she's also a really nice kid. She's too sweet and humble to boast and brag. And that means we can root for her when she puts her awesome smarts on display.
Quote 9
"You are so much wiser than your years, my dear," Miss Honey went on, "that it quite staggers me. Although you look like a child, you are not really a child at all because your mind and your powers of reasoning seem to be fully grown-up. So I suppose we might call you a grown-up child, if you see what I mean." (17.12)
It's one thing for someone to be identified as really smart or really good at math. It's another for someone to be identified as mature and grown-up. Matilda is only five. But she doesn't look at the world through a five-year-old's eyes. She sees it the way a fully grown-up person would. This means she's more advanced than your average, run-of-the-mill prodigy (if there is such a thing).