[{"id": 1, "type": "short_answer", "skill": "computation", "question": "Calculate: 74 + 41", "difficulty": "medium", "explanation": "Add systematically.", "needs_review": false, "correct_answer": "115"}, {"id": 2, "type": "multiple_choice", "skill": "properties", "options": ["Commutative property", "Associative property", "Identity property", "Distributive 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 × 6", "difficulty": "medium", "explanation": "Multiply: 2×6=12", "needs_review": false, "correct_answer": "12"}, {"id": 4, "type": "short_answer", "skill": "computation", "question": "Calculate: 18 × 2", "difficulty": "medium", "explanation": "Multiply: 18×2=36", "needs_review": false, "correct_answer": "36"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 20 × 12", "difficulty": "medium", "explanation": "Multiply: 20×12=240", "needs_review": false, "correct_answer": "240"}, {"id": 6, "type": "short_answer", "skill": "computation", "question": "Calculate: 11 × 15", "difficulty": "medium", "explanation": "Multiply: 11×15=165", "needs_review": false, "correct_answer": "165"}, {"id": 7, "type": "short_answer", "skill": "computation", "question": "Calculate: 5 × 3", "difficulty": "medium", "explanation": "Multiply: 5×3=15", "needs_review": false, "correct_answer": "15"}, {"id": 8, "type": "short_answer", "skill": "computation", "question": "Calculate: 2 × 15", "difficulty": "medium", "explanation": "Multiply: 2×15=30", "needs_review": false, "correct_answer": "30"}]