[{"id": 1, "type": "short_answer", "skill": "addition", "question": "Calculate: 46 + 28", "difficulty": "medium", "explanation": "Add by place value, regrouping as needed.", "needs_review": false, "correct_answer": "74"}, {"id": 2, "type": "multiple_choice", "skill": "addition", "options": ["84", "73", "74", "79"], "question": "What is the sum of 46 and 28?", "difficulty": "easy", "explanation": "46+28=74", "needs_review": false, "correct_answer": "74"}, {"id": 3, "type": "true_false", "skill": "properties", "question": "The commutative property means 46+28 = 28+46.", "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: 16 × 19", "difficulty": "medium", "explanation": "Multiply: 16×19=304", "needs_review": false, "correct_answer": "304"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 18 × 5", "difficulty": "medium", "explanation": "Multiply: 18×5=90", "needs_review": false, "correct_answer": "90"}, {"id": 6, "type": "short_answer", "skill": "computation", "question": "Calculate: 3 × 17", "difficulty": "medium", "explanation": "Multiply: 3×17=51", "needs_review": false, "correct_answer": "51"}, {"id": 7, "type": "short_answer", "skill": "computation", "question": "Calculate: 7 × 5", "difficulty": "medium", "explanation": "Multiply: 7×5=35", "needs_review": false, "correct_answer": "35"}, {"id": 8, "type": "short_answer", "skill": "computation", "question": "Calculate: 2 × 7", "difficulty": "medium", "explanation": "Multiply: 2×7=14", "needs_review": false, "correct_answer": "14"}]