[{"id": 1, "type": "short_answer", "skill": "computation", "question": "Calculate: 40 + 87", "difficulty": "medium", "explanation": "Add systematically.", "needs_review": false, "correct_answer": "127"}, {"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: 14 × 6", "difficulty": "medium", "explanation": "Multiply: 14×6=84", "needs_review": false, "correct_answer": "84"}, {"id": 4, "type": "short_answer", "skill": "computation", "question": "Calculate: 12 × 6", "difficulty": "medium", "explanation": "Multiply: 12×6=72", "needs_review": false, "correct_answer": "72"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 9 × 12", "difficulty": "medium", "explanation": "Multiply: 9×12=108", "needs_review": false, "correct_answer": "108"}, {"id": 6, "type": "short_answer", "skill": "computation", "question": "Calculate: 11 × 4", "difficulty": "medium", "explanation": "Multiply: 11×4=44", "needs_review": false, "correct_answer": "44"}, {"id": 7, "type": "short_answer", "skill": "computation", "question": "Calculate: 4 × 9", "difficulty": "medium", "explanation": "Multiply: 4×9=36", "needs_review": false, "correct_answer": "36"}, {"id": 8, "type": "short_answer", "skill": "computation", "question": "Calculate: 9 × 7", "difficulty": "medium", "explanation": "Multiply: 9×7=63", "needs_review": false, "correct_answer": "63"}]