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?
How many books did Carlos read in July and August? ** Carlos read 28 books + 30 books = <<28+30=58>>58 books.
How many books did Carlos need to read in June? ** He needed to read 100 books - 58 books = <<100-58=42>>42 books in June.
#### 42