[{"id": 1, "type": "short_answer", "skill": "multiplication", "question": "Calculate: 9 × 7", "difficulty": "medium", "explanation": "9 groups of 7.", "needs_review": false, "correct_answer": "63"}, {"id": 2, "type": "multiple_choice", "skill": "multiplication", "options": ["56", "63", "16", "72"], "question": "What is the product of 9 and 7?", "difficulty": "easy", "explanation": "9×7=63", "needs_review": false, "correct_answer": "63"}, {"id": 3, "type": "short_answer", "skill": "computation", "question": "Calculate: 15 × 19", "difficulty": "medium", "explanation": "Multiply: 15×19=285", "needs_review": false, "correct_answer": "285"}, {"id": 4, "type": "short_answer", "skill": "computation", "question": "Calculate: 3 × 19", "difficulty": "medium", "explanation": "Multiply: 3×19=57", "needs_review": false, "correct_answer": "57"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 2 × 3", "difficulty": "medium", "explanation": "Multiply: 2×3=6", "needs_review": false, "correct_answer": "6"}, {"id": 6, "type": "short_answer", "skill": "computation", "question": "Calculate: 20 × 3", "difficulty": "medium", "explanation": "Multiply: 20×3=60", "needs_review": false, "correct_answer": "60"}, {"id": 7, "type": "short_answer", "skill": "computation", "question": "Calculate: 8 × 7", "difficulty": "medium", "explanation": "Multiply: 8×7=56", "needs_review": false, "correct_answer": "56"}, {"id": 8, "type": "short_answer", "skill": "computation", "question": "Calculate: 19 × 14", "difficulty": "medium", "explanation": "Multiply: 19×14=266", "needs_review": false, "correct_answer": "266"}]