[{"id": 1, "type": "short_answer", "skill": "computation", "question": "Calculate: 55 + 76", "difficulty": "medium", "explanation": "Add systematically.", "needs_review": false, "correct_answer": "131"}, {"id": 2, "type": "multiple_choice", "skill": "properties", "options": ["Distributive property", "Identity property", "Commutative property", "Associative property"], "question": "Which property states a+0=a?", "difficulty": "easy", "explanation": "The identity property of addition states that adding 0 to any number gives that number.", "needs_review": false, "correct_answer": "Identity property"}, {"id": 3, "type": "short_answer", "skill": "computation", "question": "Calculate: 4 × 2", "difficulty": "medium", "explanation": "Multiply: 4×2=8", "needs_review": false, "correct_answer": "8"}, {"id": 4, "type": "short_answer", "skill": "computation", "question": "Calculate: 19 × 17", "difficulty": "medium", "explanation": "Multiply: 19×17=323", "needs_review": false, "correct_answer": "323"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 5 × 16", "difficulty": "medium", "explanation": "Multiply: 5×16=80", "needs_review": false, "correct_answer": "80"}, {"id": 6, "type": "short_answer", "skill": "computation", "question": "Calculate: 17 × 16", "difficulty": "medium", "explanation": "Multiply: 17×16=272", "needs_review": false, "correct_answer": "272"}, {"id": 7, "type": "short_answer", "skill": "computation", "question": "Calculate: 17 × 15", "difficulty": "medium", "explanation": "Multiply: 17×15=255", "needs_review": false, "correct_answer": "255"}, {"id": 8, "type": "short_answer", "skill": "computation", "question": "Calculate: 4 × 18", "difficulty": "medium", "explanation": "Multiply: 4×18=72", "needs_review": false, "correct_answer": "72"}]