[{"id": 1, "type": "short_answer", "skill": "addition", "question": "Calculate: 33 + 22", "difficulty": "medium", "explanation": "Add by place value, regrouping as needed.", "needs_review": false, "correct_answer": "55"}, {"id": 2, "type": "multiple_choice", "skill": "addition", "options": ["65", "60", "55", "54"], "question": "What is the sum of 33 and 22?", "difficulty": "easy", "explanation": "33+22=55", "needs_review": false, "correct_answer": "55"}, {"id": 3, "type": "true_false", "skill": "properties", "question": "The commutative property means 33+22 = 22+33.", "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: 13 × 15", "difficulty": "medium", "explanation": "Multiply: 13×15=195", "needs_review": false, "correct_answer": "195"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 18 × 4", "difficulty": "medium", "explanation": "Multiply: 18×4=72", "needs_review": false, "correct_answer": "72"}, {"id": 6, "type": "short_answer", "skill": "computation", "question": "Calculate: 2 × 15", "difficulty": "medium", "explanation": "Multiply: 2×15=30", "needs_review": false, "correct_answer": "30"}, {"id": 7, "type": "short_answer", "skill": "computation", "question": "Calculate: 18 × 4", "difficulty": "medium", "explanation": "Multiply: 18×4=72", "needs_review": false, "correct_answer": "72"}, {"id": 8, "type": "short_answer", "skill": "computation", "question": "Calculate: 15 × 5", "difficulty": "medium", "explanation": "Multiply: 15×5=75", "needs_review": false, "correct_answer": "75"}]