[{"id": 1, "type": "short_answer", "skill": "computation", "question": "Calculate: 59 + 71", "difficulty": "medium", "explanation": "Add systematically.", "needs_review": false, "correct_answer": "130"}, {"id": 2, "type": "multiple_choice", "skill": "properties", "options": ["Commutative property", "Distributive property", "Identity 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: 2 × 11", "difficulty": "medium", "explanation": "Multiply: 2×11=22", "needs_review": false, "correct_answer": "22"}, {"id": 4, "type": "short_answer", "skill": "computation", "question": "Calculate: 7 × 13", "difficulty": "medium", "explanation": "Multiply: 7×13=91", "needs_review": false, "correct_answer": "91"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 9 × 3", "difficulty": "medium", "explanation": "Multiply: 9×3=27", "needs_review": false, "correct_answer": "27"}, {"id": 6, "type": "short_answer", "skill": "computation", "question": "Calculate: 5 × 20", "difficulty": "medium", "explanation": "Multiply: 5×20=100", "needs_review": false, "correct_answer": "100"}, {"id": 7, "type": "short_answer", "skill": "computation", "question": "Calculate: 9 × 13", "difficulty": "medium", "explanation": "Multiply: 9×13=117", "needs_review": false, "correct_answer": "117"}, {"id": 8, "type": "short_answer", "skill": "computation", "question": "Calculate: 3 × 13", "difficulty": "medium", "explanation": "Multiply: 3×13=39", "needs_review": false, "correct_answer": "39"}]