[{"id": 1, "type": "short_answer", "skill": "computation", "question": "Calculate: 73 + 25", "difficulty": "medium", "explanation": "Add systematically.", "needs_review": false, "correct_answer": "98"}, {"id": 2, "type": "multiple_choice", "skill": "properties", "options": ["Associative property", "Distributive property", "Commutative property", "Identity 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: 3 × 15", "difficulty": "medium", "explanation": "Multiply: 3×15=45", "needs_review": false, "correct_answer": "45"}, {"id": 4, "type": "short_answer", "skill": "computation", "question": "Calculate: 17 × 7", "difficulty": "medium", "explanation": "Multiply: 17×7=119", "needs_review": false, "correct_answer": "119"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 2 × 19", "difficulty": "medium", "explanation": "Multiply: 2×19=38", "needs_review": false, "correct_answer": "38"}, {"id": 6, "type": "short_answer", "skill": "computation", "question": "Calculate: 15 × 20", "difficulty": "medium", "explanation": "Multiply: 15×20=300", "needs_review": false, "correct_answer": "300"}, {"id": 7, "type": "short_answer", "skill": "computation", "question": "Calculate: 12 × 12", "difficulty": "medium", "explanation": "Multiply: 12×12=144", "needs_review": false, "correct_answer": "144"}, {"id": 8, "type": "short_answer", "skill": "computation", "question": "Calculate: 12 × 4", "difficulty": "medium", "explanation": "Multiply: 12×4=48", "needs_review": false, "correct_answer": "48"}]