[{"id": 1, "type": "short_answer", "skill": "computation", "question": "Calculate: 81 + 62", "difficulty": "medium", "explanation": "Add systematically.", "needs_review": false, "correct_answer": "143"}, {"id": 2, "type": "multiple_choice", "skill": "properties", "options": ["Commutative property", "Associative 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: 11 × 18", "difficulty": "medium", "explanation": "Multiply: 11×18=198", "needs_review": false, "correct_answer": "198"}, {"id": 4, "type": "short_answer", "skill": "computation", "question": "Calculate: 9 × 6", "difficulty": "medium", "explanation": "Multiply: 9×6=54", "needs_review": false, "correct_answer": "54"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 8 × 16", "difficulty": "medium", "explanation": "Multiply: 8×16=128", "needs_review": false, "correct_answer": "128"}, {"id": 6, "type": "short_answer", "skill": "computation", "question": "Calculate: 4 × 3", "difficulty": "medium", "explanation": "Multiply: 4×3=12", "needs_review": false, "correct_answer": "12"}, {"id": 7, "type": "short_answer", "skill": "computation", "question": "Calculate: 6 × 8", "difficulty": "medium", "explanation": "Multiply: 6×8=48", "needs_review": false, "correct_answer": "48"}, {"id": 8, "type": "short_answer", "skill": "computation", "question": "Calculate: 18 × 2", "difficulty": "medium", "explanation": "Multiply: 18×2=36", "needs_review": false, "correct_answer": "36"}]