[{"title": "Basic Addition", "content": "Add 67 + 74. Start in the ones place: 7 + 4 = 11. Since the sum is 10 or more, write 1 and carry 1. Continue to the tens place.", "solution": "67 + 74 = 141"}, {"title": "Word Problem", "content": "A library has 437 fiction books and 373 nonfiction books. How many books does the library have in total? Identify the operation: we are combining two quantities, so we add.", "solution": "437 + 373 = 810 books"}]