[{"id": 1, "type": "short_answer", "skill": "computation", "question": "Calculate: 33 + 48", "difficulty": "medium", "explanation": "Add systematically.", "needs_review": false, "correct_answer": "81"}, {"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: 10 × 20", "difficulty": "medium", "explanation": "Multiply: 10×20=200", "needs_review": false, "correct_answer": "200"}, {"id": 4, "type": "short_answer", "skill": "computation", "question": "Calculate: 20 × 7", "difficulty": "medium", "explanation": "Multiply: 20×7=140", "needs_review": false, "correct_answer": "140"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 2 × 16", "difficulty": "medium", "explanation": "Multiply: 2×16=32", "needs_review": false, "correct_answer": "32"}, {"id": 6, "type": "short_answer", "skill": "computation", "question": "Calculate: 2 × 13", "difficulty": "medium", "explanation": "Multiply: 2×13=26", "needs_review": false, "correct_answer": "26"}, {"id": 7, "type": "short_answer", "skill": "computation", "question": "Calculate: 14 × 9", "difficulty": "medium", "explanation": "Multiply: 14×9=126", "needs_review": false, "correct_answer": "126"}, {"id": 8, "type": "short_answer", "skill": "computation", "question": "Calculate: 11 × 19", "difficulty": "medium", "explanation": "Multiply: 11×19=209", "needs_review": false, "correct_answer": "209"}]