[{"id": 1, "type": "short_answer", "skill": "computation", "question": "Calculate: 36 + 42", "difficulty": "medium", "explanation": "Add systematically.", "needs_review": false, "correct_answer": "78"}, {"id": 2, "type": "multiple_choice", "skill": "properties", "options": ["Identity property", "Distributive property", "Commutative property", "Associative 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: 4 × 10", "difficulty": "medium", "explanation": "Multiply: 4×10=40", "needs_review": false, "correct_answer": "40"}, {"id": 4, "type": "short_answer", "skill": "computation", "question": "Calculate: 16 × 18", "difficulty": "medium", "explanation": "Multiply: 16×18=288", "needs_review": false, "correct_answer": "288"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 18 × 14", "difficulty": "medium", "explanation": "Multiply: 18×14=252", "needs_review": false, "correct_answer": "252"}]