[{"id": 1, "type": "short_answer", "skill": "computation", "question": "Calculate: 58 + 85", "difficulty": "medium", "explanation": "Add systematically.", "needs_review": false, "correct_answer": "143"}, {"id": 2, "type": "multiple_choice", "skill": "properties", "options": ["Distributive property", "Associative property", "Identity 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: 5 × 13", "difficulty": "medium", "explanation": "Multiply: 5×13=65", "needs_review": false, "correct_answer": "65"}, {"id": 4, "type": "short_answer", "skill": "computation", "question": "Calculate: 6 × 5", "difficulty": "medium", "explanation": "Multiply: 6×5=30", "needs_review": false, "correct_answer": "30"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 19 × 19", "difficulty": "medium", "explanation": "Multiply: 19×19=361", "needs_review": false, "correct_answer": "361"}, {"id": 6, "type": "short_answer", "skill": "computation", "question": "Calculate: 15 × 10", "difficulty": "medium", "explanation": "Multiply: 15×10=150", "needs_review": false, "correct_answer": "150"}, {"id": 7, "type": "short_answer", "skill": "computation", "question": "Calculate: 16 × 2", "difficulty": "medium", "explanation": "Multiply: 16×2=32", "needs_review": false, "correct_answer": "32"}, {"id": 8, "type": "short_answer", "skill": "computation", "question": "Calculate: 4 × 3", "difficulty": "medium", "explanation": "Multiply: 4×3=12", "needs_review": false, "correct_answer": "12"}]