[{"id": 1, "type": "short_answer", "skill": "computation", "question": "Calculate: 10 + 55", "difficulty": "medium", "explanation": "Add systematically.", "needs_review": false, "correct_answer": "65"}, {"id": 2, "type": "multiple_choice", "skill": "properties", "options": ["Identity property", "Distributive property", "Associative property", "Commutative 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: 2 × 2", "difficulty": "medium", "explanation": "Multiply: 2×2=4", "needs_review": false, "correct_answer": "4"}, {"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: 15 × 20", "difficulty": "medium", "explanation": "Multiply: 15×20=300", "needs_review": false, "correct_answer": "300"}, {"id": 6, "type": "short_answer", "skill": "computation", "question": "Calculate: 6 × 10", "difficulty": "medium", "explanation": "Multiply: 6×10=60", "needs_review": false, "correct_answer": "60"}, {"id": 7, "type": "short_answer", "skill": "computation", "question": "Calculate: 12 × 6", "difficulty": "medium", "explanation": "Multiply: 12×6=72", "needs_review": false, "correct_answer": "72"}, {"id": 8, "type": "short_answer", "skill": "computation", "question": "Calculate: 12 × 19", "difficulty": "medium", "explanation": "Multiply: 12×19=228", "needs_review": false, "correct_answer": "228"}]