[{"id": 1, "type": "short_answer", "skill": "computation", "question": "Calculate: 88 + 11", "difficulty": "medium", "explanation": "Add systematically.", "needs_review": false, "correct_answer": "99"}, {"id": 2, "type": "multiple_choice", "skill": "properties", "options": ["Identity property", "Commutative property", "Associative property", "Distributive 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: 13 × 13", "difficulty": "medium", "explanation": "Multiply: 13×13=169", "needs_review": false, "correct_answer": "169"}, {"id": 4, "type": "short_answer", "skill": "computation", "question": "Calculate: 15 × 19", "difficulty": "medium", "explanation": "Multiply: 15×19=285", "needs_review": false, "correct_answer": "285"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 9 × 7", "difficulty": "medium", "explanation": "Multiply: 9×7=63", "needs_review": false, "correct_answer": "63"}, {"id": 6, "type": "short_answer", "skill": "computation", "question": "Calculate: 12 × 10", "difficulty": "medium", "explanation": "Multiply: 12×10=120", "needs_review": false, "correct_answer": "120"}, {"id": 7, "type": "short_answer", "skill": "computation", "question": "Calculate: 4 × 17", "difficulty": "medium", "explanation": "Multiply: 4×17=68", "needs_review": false, "correct_answer": "68"}, {"id": 8, "type": "short_answer", "skill": "computation", "question": "Calculate: 4 × 13", "difficulty": "medium", "explanation": "Multiply: 4×13=52", "needs_review": false, "correct_answer": "52"}, {"id": 9, "type": "short_answer", "skill": "computation", "question": "Calculate: 17 × 14", "difficulty": "medium", "explanation": "Multiply: 17×14=238", "needs_review": false, "correct_answer": "238"}, {"id": 10, "type": "short_answer", "skill": "computation", "question": "Calculate: 7 × 16", "difficulty": "medium", "explanation": "Multiply: 7×16=112", "needs_review": false, "correct_answer": "112"}, {"id": 11, "type": "short_answer", "skill": "computation", "question": "Calculate: 14 × 20", "difficulty": "medium", "explanation": "Multiply: 14×20=280", "needs_review": false, "correct_answer": "280"}, {"id": 12, "type": "short_answer", "skill": "computation", "question": "Calculate: 2 × 20", "difficulty": "medium", "explanation": "Multiply: 2×20=40", "needs_review": false, "correct_answer": "40"}]