[{"id": 1, "type": "short_answer", "skill": "computation", "question": "Calculate: 34 + 77", "difficulty": "medium", "explanation": "Add systematically.", "needs_review": false, "correct_answer": "111"}, {"id": 2, "type": "multiple_choice", "skill": "properties", "options": ["Associative property", "Commutative property", "Distributive property", "Identity 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: 19 × 8", "difficulty": "medium", "explanation": "Multiply: 19×8=152", "needs_review": false, "correct_answer": "152"}, {"id": 4, "type": "short_answer", "skill": "computation", "question": "Calculate: 15 × 7", "difficulty": "medium", "explanation": "Multiply: 15×7=105", "needs_review": false, "correct_answer": "105"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 8 × 12", "difficulty": "medium", "explanation": "Multiply: 8×12=96", "needs_review": false, "correct_answer": "96"}]