[{"id": 1, "type": "short_answer", "skill": "computation", "question": "Calculate: 69 + 12", "difficulty": "medium", "explanation": "Add systematically.", "needs_review": false, "correct_answer": "81"}, {"id": 2, "type": "multiple_choice", "skill": "properties", "options": ["Identity property", "Distributive property", "Associative property", "Commutative 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: 6 × 3", "difficulty": "medium", "explanation": "Multiply: 6×3=18", "needs_review": false, "correct_answer": "18"}, {"id": 4, "type": "short_answer", "skill": "computation", "question": "Calculate: 5 × 15", "difficulty": "medium", "explanation": "Multiply: 5×15=75", "needs_review": false, "correct_answer": "75"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 20 × 10", "difficulty": "medium", "explanation": "Multiply: 20×10=200", "needs_review": false, "correct_answer": "200"}, {"id": 6, "type": "short_answer", "skill": "computation", "question": "Calculate: 5 × 4", "difficulty": "medium", "explanation": "Multiply: 5×4=20", "needs_review": false, "correct_answer": "20"}, {"id": 7, "type": "short_answer", "skill": "computation", "question": "Calculate: 14 × 6", "difficulty": "medium", "explanation": "Multiply: 14×6=84", "needs_review": false, "correct_answer": "84"}, {"id": 8, "type": "short_answer", "skill": "computation", "question": "Calculate: 17 × 10", "difficulty": "medium", "explanation": "Multiply: 17×10=170", "needs_review": false, "correct_answer": "170"}, {"id": 9, "type": "short_answer", "skill": "computation", "question": "Calculate: 7 × 17", "difficulty": "medium", "explanation": "Multiply: 7×17=119", "needs_review": false, "correct_answer": "119"}, {"id": 10, "type": "short_answer", "skill": "computation", "question": "Calculate: 19 × 12", "difficulty": "medium", "explanation": "Multiply: 19×12=228", "needs_review": false, "correct_answer": "228"}, {"id": 11, "type": "short_answer", "skill": "computation", "question": "Calculate: 9 × 7", "difficulty": "medium", "explanation": "Multiply: 9×7=63", "needs_review": false, "correct_answer": "63"}, {"id": 12, "type": "short_answer", "skill": "computation", "question": "Calculate: 13 × 15", "difficulty": "medium", "explanation": "Multiply: 13×15=195", "needs_review": false, "correct_answer": "195"}]