[{"id": 1, "type": "short_answer", "skill": "computation", "question": "Calculate: 49 + 98", "difficulty": "medium", "explanation": "Add systematically.", "needs_review": false, "correct_answer": "147"}, {"id": 2, "type": "multiple_choice", "skill": "properties", "options": ["Identity property", "Distributive property", "Associative 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: 4 × 4", "difficulty": "medium", "explanation": "Multiply: 4×4=16", "needs_review": false, "correct_answer": "16"}, {"id": 4, "type": "short_answer", "skill": "computation", "question": "Calculate: 16 × 12", "difficulty": "medium", "explanation": "Multiply: 16×12=192", "needs_review": false, "correct_answer": "192"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 7 × 4", "difficulty": "medium", "explanation": "Multiply: 7×4=28", "needs_review": false, "correct_answer": "28"}, {"id": 6, "type": "short_answer", "skill": "computation", "question": "Calculate: 17 × 11", "difficulty": "medium", "explanation": "Multiply: 17×11=187", "needs_review": false, "correct_answer": "187"}, {"id": 7, "type": "short_answer", "skill": "computation", "question": "Calculate: 9 × 12", "difficulty": "medium", "explanation": "Multiply: 9×12=108", "needs_review": false, "correct_answer": "108"}, {"id": 8, "type": "short_answer", "skill": "computation", "question": "Calculate: 3 × 3", "difficulty": "medium", "explanation": "Multiply: 3×3=9", "needs_review": false, "correct_answer": "9"}]