[{"id": 1, "type": "short_answer", "skill": "multiplication", "question": "Calculate: 4 × 4", "difficulty": "medium", "explanation": "4 groups of 4.", "needs_review": false, "correct_answer": "16"}, {"id": 2, "type": "multiple_choice", "skill": "multiplication", "options": ["12", "20", "16", "8"], "question": "What is the product of 4 and 4?", "difficulty": "easy", "explanation": "4×4=16", "needs_review": false, "correct_answer": "16"}, {"id": 3, "type": "short_answer", "skill": "computation", "question": "Calculate: 8 × 14", "difficulty": "medium", "explanation": "Multiply: 8×14=112", "needs_review": false, "correct_answer": "112"}, {"id": 4, "type": "short_answer", "skill": "computation", "question": "Calculate: 10 × 7", "difficulty": "medium", "explanation": "Multiply: 10×7=70", "needs_review": false, "correct_answer": "70"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 5 × 10", "difficulty": "medium", "explanation": "Multiply: 5×10=50", "needs_review": false, "correct_answer": "50"}]