[{"id": 1, "type": "short_answer", "skill": "computation", "question": "Calculate: 68 + 60", "difficulty": "medium", "explanation": "Add systematically.", "needs_review": false, "correct_answer": "128"}, {"id": 2, "type": "multiple_choice", "skill": "properties", "options": ["Associative property", "Commutative property", "Distributive property", "Identity 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: 10 × 6", "difficulty": "medium", "explanation": "Multiply: 10×6=60", "needs_review": false, "correct_answer": "60"}, {"id": 4, "type": "short_answer", "skill": "computation", "question": "Calculate: 9 × 9", "difficulty": "medium", "explanation": "Multiply: 9×9=81", "needs_review": false, "correct_answer": "81"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 16 × 16", "difficulty": "medium", "explanation": "Multiply: 16×16=256", "needs_review": false, "correct_answer": "256"}]