[{"id": 1, "type": "short_answer", "skill": "computation", "question": "Calculate: 67 + 24", "difficulty": "medium", "explanation": "Add systematically.", "needs_review": false, "correct_answer": "91"}, {"id": 2, "type": "multiple_choice", "skill": "properties", "options": ["Associative property", "Commutative property", "Distributive 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: 2 × 10", "difficulty": "medium", "explanation": "Multiply: 2×10=20", "needs_review": false, "correct_answer": "20"}, {"id": 4, "type": "short_answer", "skill": "computation", "question": "Calculate: 6 × 17", "difficulty": "medium", "explanation": "Multiply: 6×17=102", "needs_review": false, "correct_answer": "102"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 3 × 3", "difficulty": "medium", "explanation": "Multiply: 3×3=9", "needs_review": false, "correct_answer": "9"}, {"id": 6, "type": "short_answer", "skill": "computation", "question": "Calculate: 3 × 7", "difficulty": "medium", "explanation": "Multiply: 3×7=21", "needs_review": false, "correct_answer": "21"}, {"id": 7, "type": "short_answer", "skill": "computation", "question": "Calculate: 13 × 16", "difficulty": "medium", "explanation": "Multiply: 13×16=208", "needs_review": false, "correct_answer": "208"}, {"id": 8, "type": "short_answer", "skill": "computation", "question": "Calculate: 6 × 18", "difficulty": "medium", "explanation": "Multiply: 6×18=108", "needs_review": false, "correct_answer": "108"}, {"id": 9, "type": "short_answer", "skill": "computation", "question": "Calculate: 10 × 18", "difficulty": "medium", "explanation": "Multiply: 10×18=180", "needs_review": false, "correct_answer": "180"}, {"id": 10, "type": "short_answer", "skill": "computation", "question": "Calculate: 18 × 19", "difficulty": "medium", "explanation": "Multiply: 18×19=342", "needs_review": false, "correct_answer": "342"}, {"id": 11, "type": "short_answer", "skill": "computation", "question": "Calculate: 14 × 17", "difficulty": "medium", "explanation": "Multiply: 14×17=238", "needs_review": false, "correct_answer": "238"}, {"id": 12, "type": "short_answer", "skill": "computation", "question": "Calculate: 8 × 16", "difficulty": "medium", "explanation": "Multiply: 8×16=128", "needs_review": false, "correct_answer": "128"}]