[{"id": 1, "type": "short_answer", "skill": "computation", "question": "Calculate: 72 + 49", "difficulty": "medium", "explanation": "Add systematically.", "needs_review": false, "correct_answer": "121"}, {"id": 2, "type": "multiple_choice", "skill": "properties", "options": ["Commutative property", "Distributive property", "Identity property", "Associative 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: 17 × 3", "difficulty": "medium", "explanation": "Multiply: 17×3=51", "needs_review": false, "correct_answer": "51"}, {"id": 4, "type": "short_answer", "skill": "computation", "question": "Calculate: 2 × 12", "difficulty": "medium", "explanation": "Multiply: 2×12=24", "needs_review": false, "correct_answer": "24"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 16 × 12", "difficulty": "medium", "explanation": "Multiply: 16×12=192", "needs_review": false, "correct_answer": "192"}, {"id": 6, "type": "short_answer", "skill": "computation", "question": "Calculate: 10 × 9", "difficulty": "medium", "explanation": "Multiply: 10×9=90", "needs_review": false, "correct_answer": "90"}, {"id": 7, "type": "short_answer", "skill": "computation", "question": "Calculate: 5 × 6", "difficulty": "medium", "explanation": "Multiply: 5×6=30", "needs_review": false, "correct_answer": "30"}, {"id": 8, "type": "short_answer", "skill": "computation", "question": "Calculate: 8 × 8", "difficulty": "medium", "explanation": "Multiply: 8×8=64", "needs_review": false, "correct_answer": "64"}]