[{"id": 1, "type": "short_answer", "skill": "addition", "question": "Calculate: 17 + 26", "difficulty": "medium", "explanation": "Add by place value, regrouping as needed.", "needs_review": false, "correct_answer": "43"}, {"id": 2, "type": "multiple_choice", "skill": "addition", "options": ["42", "48", "53", "43"], "question": "What is the sum of 17 and 26?", "difficulty": "easy", "explanation": "17+26=43", "needs_review": false, "correct_answer": "43"}, {"id": 3, "type": "true_false", "skill": "properties", "question": "The commutative property means 17+26 = 26+17.", "difficulty": "easy", "explanation": "The commutative property states changing the order of addends does not change the sum.", "needs_review": false, "correct_answer": "True"}, {"id": 4, "type": "short_answer", "skill": "computation", "question": "Calculate: 14 × 12", "difficulty": "medium", "explanation": "Multiply: 14×12=168", "needs_review": false, "correct_answer": "168"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 18 × 18", "difficulty": "medium", "explanation": "Multiply: 18×18=324", "needs_review": false, "correct_answer": "324"}]