[{"id": 1, "type": "short_answer", "skill": "computation", "question": "Calculate: 60 + 13", "difficulty": "medium", "explanation": "Add systematically.", "needs_review": false, "correct_answer": "73"}, {"id": 2, "type": "multiple_choice", "skill": "properties", "options": ["Associative property", "Distributive property", "Commutative 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: 4 × 7", "difficulty": "medium", "explanation": "Multiply: 4×7=28", "needs_review": false, "correct_answer": "28"}, {"id": 4, "type": "short_answer", "skill": "computation", "question": "Calculate: 9 × 4", "difficulty": "medium", "explanation": "Multiply: 9×4=36", "needs_review": false, "correct_answer": "36"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 11 × 13", "difficulty": "medium", "explanation": "Multiply: 11×13=143", "needs_review": false, "correct_answer": "143"}, {"id": 6, "type": "short_answer", "skill": "computation", "question": "Calculate: 13 × 19", "difficulty": "medium", "explanation": "Multiply: 13×19=247", "needs_review": false, "correct_answer": "247"}, {"id": 7, "type": "short_answer", "skill": "computation", "question": "Calculate: 19 × 9", "difficulty": "medium", "explanation": "Multiply: 19×9=171", "needs_review": false, "correct_answer": "171"}, {"id": 8, "type": "short_answer", "skill": "computation", "question": "Calculate: 13 × 11", "difficulty": "medium", "explanation": "Multiply: 13×11=143", "needs_review": false, "correct_answer": "143"}]