[{"id": 1, "type": "short_answer", "skill": "computation", "question": "Calculate: 11 + 40", "difficulty": "medium", "explanation": "Add systematically.", "needs_review": false, "correct_answer": "51"}, {"id": 2, "type": "multiple_choice", "skill": "properties", "options": ["Associative property", "Identity property", "Commutative 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: 13 × 20", "difficulty": "medium", "explanation": "Multiply: 13×20=260", "needs_review": false, "correct_answer": "260"}, {"id": 4, "type": "short_answer", "skill": "computation", "question": "Calculate: 8 × 5", "difficulty": "medium", "explanation": "Multiply: 8×5=40", "needs_review": false, "correct_answer": "40"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 6 × 10", "difficulty": "medium", "explanation": "Multiply: 6×10=60", "needs_review": false, "correct_answer": "60"}, {"id": 6, "type": "short_answer", "skill": "computation", "question": "Calculate: 15 × 8", "difficulty": "medium", "explanation": "Multiply: 15×8=120", "needs_review": false, "correct_answer": "120"}, {"id": 7, "type": "short_answer", "skill": "computation", "question": "Calculate: 4 × 7", "difficulty": "medium", "explanation": "Multiply: 4×7=28", "needs_review": false, "correct_answer": "28"}, {"id": 8, "type": "short_answer", "skill": "computation", "question": "Calculate: 3 × 14", "difficulty": "medium", "explanation": "Multiply: 3×14=42", "needs_review": false, "correct_answer": "42"}]