[{"id": 1, "type": "short_answer", "skill": "computation", "question": "Calculate: 69 + 98", "difficulty": "medium", "explanation": "Add systematically.", "needs_review": false, "correct_answer": "167"}, {"id": 2, "type": "multiple_choice", "skill": "properties", "options": ["Identity property", "Commutative property", "Distributive 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: 20 × 14", "difficulty": "medium", "explanation": "Multiply: 20×14=280", "needs_review": false, "correct_answer": "280"}, {"id": 4, "type": "short_answer", "skill": "computation", "question": "Calculate: 16 × 13", "difficulty": "medium", "explanation": "Multiply: 16×13=208", "needs_review": false, "correct_answer": "208"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 14 × 10", "difficulty": "medium", "explanation": "Multiply: 14×10=140", "needs_review": false, "correct_answer": "140"}]