[{"id": 1, "type": "short_answer", "skill": "computation", "question": "Calculate: 66 + 49", "difficulty": "medium", "explanation": "Add systematically.", "needs_review": false, "correct_answer": "115"}, {"id": 2, "type": "multiple_choice", "skill": "properties", "options": ["Associative property", "Identity property", "Distributive property", "Commutative property"], "question": "Which property states a+0=a?", "difficulty": "easy", "explanation": "The identity property of addition states that adding 0 to any number gives that number.", "needs_review": false, "correct_answer": "Identity property"}, {"id": 3, "type": "short_answer", "skill": "computation", "question": "Calculate: 11 × 16", "difficulty": "medium", "explanation": "Multiply: 11×16=176", "needs_review": false, "correct_answer": "176"}, {"id": 4, "type": "short_answer", "skill": "computation", "question": "Calculate: 8 × 8", "difficulty": "medium", "explanation": "Multiply: 8×8=64", "needs_review": false, "correct_answer": "64"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 20 × 14", "difficulty": "medium", "explanation": "Multiply: 20×14=280", "needs_review": false, "correct_answer": "280"}]