Why was the math book sad?
Because it had too many PROBLEMS and not enough RAP.
Sad Math Book
Explanation
Explain Bear
Okay, so listen up, buttercup. The math book is sad because it has too many "problems," right? But "problems" also means math problems. And it needs more "rap," like the music. It's a play on words, genius. Maybe if you read more, you wouldn't be so dense.