[{"id": 1, "type": "short_answer", "skill": "subtraction", "question": "Calculate: 88 − 79", "difficulty": "medium", "explanation": "Subtract by place value, borrowing as needed.", "needs_review": false, "correct_answer": "9"}, {"id": 2, "type": "multiple_choice", "skill": "subtraction", "options": ["9", "167", "10", "7"], "question": "What is 88 − 79?", "difficulty": "easy", "explanation": "88-79=9", "needs_review": false, "correct_answer": "9"}, {"id": 3, "type": "short_answer", "skill": "computation", "question": "Calculate: 2 × 6", "difficulty": "medium", "explanation": "Multiply: 2×6=12", "needs_review": false, "correct_answer": "12"}, {"id": 4, "type": "short_answer", "skill": "computation", "question": "Calculate: 20 × 17", "difficulty": "medium", "explanation": "Multiply: 20×17=340", "needs_review": false, "correct_answer": "340"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 4 × 11", "difficulty": "medium", "explanation": "Multiply: 4×11=44", "needs_review": false, "correct_answer": "44"}]