[{"id": 1, "type": "short_answer", "skill": "computation", "question": "Calculate: 98 + 90", "difficulty": "medium", "explanation": "Add systematically.", "needs_review": false, "correct_answer": "188"}, {"id": 2, "type": "multiple_choice", "skill": "properties", "options": ["Associative property", "Commutative 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: 3 × 4", "difficulty": "medium", "explanation": "Multiply: 3×4=12", "needs_review": false, "correct_answer": "12"}, {"id": 4, "type": "short_answer", "skill": "computation", "question": "Calculate: 11 × 18", "difficulty": "medium", "explanation": "Multiply: 11×18=198", "needs_review": false, "correct_answer": "198"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 10 × 6", "difficulty": "medium", "explanation": "Multiply: 10×6=60", "needs_review": false, "correct_answer": "60"}, {"id": 6, "type": "short_answer", "skill": "computation", "question": "Calculate: 7 × 2", "difficulty": "medium", "explanation": "Multiply: 7×2=14", "needs_review": false, "correct_answer": "14"}, {"id": 7, "type": "short_answer", "skill": "computation", "question": "Calculate: 20 × 5", "difficulty": "medium", "explanation": "Multiply: 20×5=100", "needs_review": false, "correct_answer": "100"}, {"id": 8, "type": "short_answer", "skill": "computation", "question": "Calculate: 18 × 3", "difficulty": "medium", "explanation": "Multiply: 18×3=54", "needs_review": false, "correct_answer": "54"}, {"id": 9, "type": "short_answer", "skill": "computation", "question": "Calculate: 19 × 5", "difficulty": "medium", "explanation": "Multiply: 19×5=95", "needs_review": false, "correct_answer": "95"}, {"id": 10, "type": "short_answer", "skill": "computation", "question": "Calculate: 12 × 9", "difficulty": "medium", "explanation": "Multiply: 12×9=108", "needs_review": false, "correct_answer": "108"}, {"id": 11, "type": "short_answer", "skill": "computation", "question": "Calculate: 14 × 16", "difficulty": "medium", "explanation": "Multiply: 14×16=224", "needs_review": false, "correct_answer": "224"}, {"id": 12, "type": "short_answer", "skill": "computation", "question": "Calculate: 4 × 16", "difficulty": "medium", "explanation": "Multiply: 4×16=64", "needs_review": false, "correct_answer": "64"}]