[{"id": 1, "type": "short_answer", "skill": "addition", "question": "Calculate: 416 + 445", "difficulty": "medium", "explanation": "Add by place value, regrouping as needed.", "needs_review": false, "correct_answer": "861"}, {"id": 2, "type": "multiple_choice", "skill": "addition", "options": ["871", "860", "861", "866"], "question": "What is the sum of 416 and 445?", "difficulty": "easy", "explanation": "416+445=861", "needs_review": false, "correct_answer": "861"}, {"id": 3, "type": "true_false", "skill": "properties", "question": "The commutative property means 416+445 = 445+416.", "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: 8 × 4", "difficulty": "medium", "explanation": "Multiply: 8×4=32", "needs_review": false, "correct_answer": "32"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 8 × 5", "difficulty": "medium", "explanation": "Multiply: 8×5=40", "needs_review": false, "correct_answer": "40"}]