[{"id": 1, "type": "short_answer", "skill": "multiplication", "question": "Calculate: 12 × 11", "difficulty": "medium", "explanation": "12 groups of 11.", "needs_review": false, "correct_answer": "132"}, {"id": 2, "type": "multiple_choice", "skill": "multiplication", "options": ["121", "144", "132", "23"], "question": "What is the product of 12 and 11?", "difficulty": "easy", "explanation": "12×11=132", "needs_review": false, "correct_answer": "132"}, {"id": 3, "type": "short_answer", "skill": "computation", "question": "Calculate: 5 × 3", "difficulty": "medium", "explanation": "Multiply: 5×3=15", "needs_review": false, "correct_answer": "15"}, {"id": 4, "type": "short_answer", "skill": "computation", "question": "Calculate: 18 × 12", "difficulty": "medium", "explanation": "Multiply: 18×12=216", "needs_review": false, "correct_answer": "216"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 5 × 6", "difficulty": "medium", "explanation": "Multiply: 5×6=30", "needs_review": false, "correct_answer": "30"}]