[{"id": 1, "type": "short_answer", "skill": "computation", "question": "Calculate: 77 + 67", "difficulty": "medium", "explanation": "Add systematically.", "needs_review": false, "correct_answer": "144"}, {"id": 2, "type": "multiple_choice", "skill": "properties", "options": ["Commutative property", "Associative property", "Identity 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: 9 × 17", "difficulty": "medium", "explanation": "Multiply: 9×17=153", "needs_review": false, "correct_answer": "153"}, {"id": 4, "type": "short_answer", "skill": "computation", "question": "Calculate: 4 × 2", "difficulty": "medium", "explanation": "Multiply: 4×2=8", "needs_review": false, "correct_answer": "8"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 8 × 14", "difficulty": "medium", "explanation": "Multiply: 8×14=112", "needs_review": false, "correct_answer": "112"}]