[{"id": 1, "type": "short_answer", "skill": "computation", "question": "Calculate: 35 + 83", "difficulty": "medium", "explanation": "Add systematically.", "needs_review": false, "correct_answer": "118"}, {"id": 2, "type": "multiple_choice", "skill": "properties", "options": ["Associative property", "Commutative property", "Identity property", "Distributive 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 × 16", "difficulty": "medium", "explanation": "Multiply: 10×16=160", "needs_review": false, "correct_answer": "160"}, {"id": 4, "type": "short_answer", "skill": "computation", "question": "Calculate: 20 × 6", "difficulty": "medium", "explanation": "Multiply: 20×6=120", "needs_review": false, "correct_answer": "120"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 20 × 10", "difficulty": "medium", "explanation": "Multiply: 20×10=200", "needs_review": false, "correct_answer": "200"}]