Carlos read 28 books in July and 30 books in August. He needed to read 100 books during his summer vacation. If Carlos read some of the books in June, calculate the number of books that Carlos read in June to meet his goal? Let's answer step by step:
Carlos read 28 books + 30 books = 58 books. He needed to read 100 books - 58 books = 42 books in June. The answer: 42.