[{"title": "Basic Subtraction", "content": "Subtract 63 − 49. Ones place: 3 − 9. Since 3 < 9, borrow from the tens place.", "solution": "63 − 49 = 14"}, {"title": "Checking with Addition", "content": "If 85 − 37 = 48, check by adding: 48 + 37 = 85. ✓ Correct.", "solution": "85 − 37 = 48"}]