[{"id": 1, "type": "short_answer", "skill": "subtraction", "question": "Calculate: 552 − 477", "difficulty": "medium", "explanation": "Subtract by place value, borrowing as needed.", "needs_review": false, "correct_answer": "75"}, {"id": 2, "type": "multiple_choice", "skill": "subtraction", "options": ["75", "1029", "76", "73"], "question": "What is 552 − 477?", "difficulty": "easy", "explanation": "552-477=75", "needs_review": false, "correct_answer": "75"}, {"id": 3, "type": "short_answer", "skill": "computation", "question": "Calculate: 10 × 8", "difficulty": "medium", "explanation": "Multiply: 10×8=80", "needs_review": false, "correct_answer": "80"}, {"id": 4, "type": "short_answer", "skill": "computation", "question": "Calculate: 3 × 4", "difficulty": "medium", "explanation": "Multiply: 3×4=12", "needs_review": false, "correct_answer": "12"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 8 × 13", "difficulty": "medium", "explanation": "Multiply: 8×13=104", "needs_review": false, "correct_answer": "104"}, {"id": 6, "type": "short_answer", "skill": "computation", "question": "Calculate: 8 × 8", "difficulty": "medium", "explanation": "Multiply: 8×8=64", "needs_review": false, "correct_answer": "64"}, {"id": 7, "type": "short_answer", "skill": "computation", "question": "Calculate: 11 × 18", "difficulty": "medium", "explanation": "Multiply: 11×18=198", "needs_review": false, "correct_answer": "198"}, {"id": 8, "type": "short_answer", "skill": "computation", "question": "Calculate: 11 × 18", "difficulty": "medium", "explanation": "Multiply: 11×18=198", "needs_review": false, "correct_answer": "198"}]