[{"id": 1, "type": "short_answer", "skill": "computation", "question": "Calculate: 28 + 60", "difficulty": "medium", "explanation": "Add systematically.", "needs_review": false, "correct_answer": "88"}, {"id": 2, "type": "multiple_choice", "skill": "properties", "options": ["Commutative property", "Identity property", "Associative 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: 3 × 14", "difficulty": "medium", "explanation": "Multiply: 3×14=42", "needs_review": false, "correct_answer": "42"}, {"id": 4, "type": "short_answer", "skill": "computation", "question": "Calculate: 10 × 4", "difficulty": "medium", "explanation": "Multiply: 10×4=40", "needs_review": false, "correct_answer": "40"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 11 × 12", "difficulty": "medium", "explanation": "Multiply: 11×12=132", "needs_review": false, "correct_answer": "132"}, {"id": 6, "type": "short_answer", "skill": "computation", "question": "Calculate: 2 × 11", "difficulty": "medium", "explanation": "Multiply: 2×11=22", "needs_review": false, "correct_answer": "22"}, {"id": 7, "type": "short_answer", "skill": "computation", "question": "Calculate: 20 × 9", "difficulty": "medium", "explanation": "Multiply: 20×9=180", "needs_review": false, "correct_answer": "180"}, {"id": 8, "type": "short_answer", "skill": "computation", "question": "Calculate: 2 × 9", "difficulty": "medium", "explanation": "Multiply: 2×9=18", "needs_review": false, "correct_answer": "18"}]