[{"id": 1, "type": "short_answer", "skill": "multiplication", "question": "Calculate: 6 × 10", "difficulty": "medium", "explanation": "6 groups of 10.", "needs_review": false, "correct_answer": "60"}, {"id": 2, "type": "multiple_choice", "skill": "multiplication", "options": ["60", "66", "50", "16"], "question": "What is the product of 6 and 10?", "difficulty": "easy", "explanation": "6×10=60", "needs_review": false, "correct_answer": "60"}, {"id": 3, "type": "short_answer", "skill": "computation", "question": "Calculate: 4 × 12", "difficulty": "medium", "explanation": "Multiply: 4×12=48", "needs_review": false, "correct_answer": "48"}, {"id": 4, "type": "short_answer", "skill": "computation", "question": "Calculate: 20 × 2", "difficulty": "medium", "explanation": "Multiply: 20×2=40", "needs_review": false, "correct_answer": "40"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 8 × 5", "difficulty": "medium", "explanation": "Multiply: 8×5=40", "needs_review": false, "correct_answer": "40"}, {"id": 6, "type": "short_answer", "skill": "computation", "question": "Calculate: 10 × 2", "difficulty": "medium", "explanation": "Multiply: 10×2=20", "needs_review": false, "correct_answer": "20"}, {"id": 7, "type": "short_answer", "skill": "computation", "question": "Calculate: 7 × 14", "difficulty": "medium", "explanation": "Multiply: 7×14=98", "needs_review": false, "correct_answer": "98"}, {"id": 8, "type": "short_answer", "skill": "computation", "question": "Calculate: 8 × 4", "difficulty": "medium", "explanation": "Multiply: 8×4=32", "needs_review": false, "correct_answer": "32"}]