[{"id": 1, "type": "short_answer", "skill": "computation", "question": "Calculate: 88 + 69", "difficulty": "medium", "explanation": "Add systematically.", "needs_review": false, "correct_answer": "157"}, {"id": 2, "type": "multiple_choice", "skill": "properties", "options": ["Identity property", "Associative property", "Distributive 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: 13 × 6", "difficulty": "medium", "explanation": "Multiply: 13×6=78", "needs_review": false, "correct_answer": "78"}, {"id": 4, "type": "short_answer", "skill": "computation", "question": "Calculate: 14 × 2", "difficulty": "medium", "explanation": "Multiply: 14×2=28", "needs_review": false, "correct_answer": "28"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 11 × 19", "difficulty": "medium", "explanation": "Multiply: 11×19=209", "needs_review": false, "correct_answer": "209"}]