[{"id": 1, "type": "short_answer", "skill": "computation", "question": "Calculate: 36 + 52", "difficulty": "medium", "explanation": "Add systematically.", "needs_review": false, "correct_answer": "88"}, {"id": 2, "type": "multiple_choice", "skill": "properties", "options": ["Distributive property", "Associative property", "Identity 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: 6 × 18", "difficulty": "medium", "explanation": "Multiply: 6×18=108", "needs_review": false, "correct_answer": "108"}, {"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: 6 × 14", "difficulty": "medium", "explanation": "Multiply: 6×14=84", "needs_review": false, "correct_answer": "84"}, {"id": 6, "type": "short_answer", "skill": "computation", "question": "Calculate: 8 × 4", "difficulty": "medium", "explanation": "Multiply: 8×4=32", "needs_review": false, "correct_answer": "32"}, {"id": 7, "type": "short_answer", "skill": "computation", "question": "Calculate: 7 × 20", "difficulty": "medium", "explanation": "Multiply: 7×20=140", "needs_review": false, "correct_answer": "140"}, {"id": 8, "type": "short_answer", "skill": "computation", "question": "Calculate: 4 × 13", "difficulty": "medium", "explanation": "Multiply: 4×13=52", "needs_review": false, "correct_answer": "52"}]