[{"id": 1, "type": "short_answer", "skill": "multiplication", "question": "Calculate: 10 × 11", "difficulty": "medium", "explanation": "10 groups of 11.", "needs_review": false, "correct_answer": "110"}, {"id": 2, "type": "multiple_choice", "skill": "multiplication", "options": ["21", "110", "99", "120"], "question": "What is the product of 10 and 11?", "difficulty": "easy", "explanation": "10×11=110", "needs_review": false, "correct_answer": "110"}, {"id": 3, "type": "short_answer", "skill": "computation", "question": "Calculate: 7 × 7", "difficulty": "medium", "explanation": "Multiply: 7×7=49", "needs_review": false, "correct_answer": "49"}, {"id": 4, "type": "short_answer", "skill": "computation", "question": "Calculate: 3 × 13", "difficulty": "medium", "explanation": "Multiply: 3×13=39", "needs_review": false, "correct_answer": "39"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 17 × 2", "difficulty": "medium", "explanation": "Multiply: 17×2=34", "needs_review": false, "correct_answer": "34"}]