[{"id": 1, "type": "short_answer", "skill": "computation", "question": "Calculate: 68 + 37", "difficulty": "medium", "explanation": "Add systematically.", "needs_review": false, "correct_answer": "105"}, {"id": 2, "type": "multiple_choice", "skill": "properties", "options": ["Distributive property", "Identity property", "Associative 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: 7 × 5", "difficulty": "medium", "explanation": "Multiply: 7×5=35", "needs_review": false, "correct_answer": "35"}, {"id": 4, "type": "short_answer", "skill": "computation", "question": "Calculate: 9 × 9", "difficulty": "medium", "explanation": "Multiply: 9×9=81", "needs_review": false, "correct_answer": "81"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 5 × 2", "difficulty": "medium", "explanation": "Multiply: 5×2=10", "needs_review": false, "correct_answer": "10"}, {"id": 6, "type": "short_answer", "skill": "computation", "question": "Calculate: 18 × 19", "difficulty": "medium", "explanation": "Multiply: 18×19=342", "needs_review": false, "correct_answer": "342"}, {"id": 7, "type": "short_answer", "skill": "computation", "question": "Calculate: 13 × 7", "difficulty": "medium", "explanation": "Multiply: 13×7=91", "needs_review": false, "correct_answer": "91"}, {"id": 8, "type": "short_answer", "skill": "computation", "question": "Calculate: 9 × 7", "difficulty": "medium", "explanation": "Multiply: 9×7=63", "needs_review": false, "correct_answer": "63"}]