[{"id": 1, "type": "short_answer", "skill": "computation", "question": "Calculate: 10 + 58", "difficulty": "medium", "explanation": "Add systematically.", "needs_review": false, "correct_answer": "68"}, {"id": 2, "type": "multiple_choice", "skill": "properties", "options": ["Associative property", "Commutative property", "Distributive property", "Identity property"], "question": "Which property states a+0=a?", "difficulty": "easy", "explanation": "The identity property of addition states that adding 0 to any number gives that number.", "needs_review": false, "correct_answer": "Identity property"}, {"id": 3, "type": "short_answer", "skill": "computation", "question": "Calculate: 5 × 6", "difficulty": "medium", "explanation": "Multiply: 5×6=30", "needs_review": false, "correct_answer": "30"}, {"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: 10 × 2", "difficulty": "medium", "explanation": "Multiply: 10×2=20", "needs_review": false, "correct_answer": "20"}, {"id": 6, "type": "short_answer", "skill": "computation", "question": "Calculate: 20 × 14", "difficulty": "medium", "explanation": "Multiply: 20×14=280", "needs_review": false, "correct_answer": "280"}, {"id": 7, "type": "short_answer", "skill": "computation", "question": "Calculate: 20 × 16", "difficulty": "medium", "explanation": "Multiply: 20×16=320", "needs_review": false, "correct_answer": "320"}, {"id": 8, "type": "short_answer", "skill": "computation", "question": "Calculate: 15 × 19", "difficulty": "medium", "explanation": "Multiply: 15×19=285", "needs_review": false, "correct_answer": "285"}]