[{"id": 1, "type": "short_answer", "skill": "computation", "question": "Calculate: 42 + 52", "difficulty": "medium", "explanation": "Add systematically.", "needs_review": false, "correct_answer": "94"}, {"id": 2, "type": "multiple_choice", "skill": "properties", "options": ["Distributive property", "Associative property", "Identity 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: 7 × 7", "difficulty": "medium", "explanation": "Multiply: 7×7=49", "needs_review": false, "correct_answer": "49"}, {"id": 4, "type": "short_answer", "skill": "computation", "question": "Calculate: 14 × 18", "difficulty": "medium", "explanation": "Multiply: 14×18=252", "needs_review": false, "correct_answer": "252"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 19 × 2", "difficulty": "medium", "explanation": "Multiply: 19×2=38", "needs_review": false, "correct_answer": "38"}, {"id": 6, "type": "short_answer", "skill": "computation", "question": "Calculate: 2 × 14", "difficulty": "medium", "explanation": "Multiply: 2×14=28", "needs_review": false, "correct_answer": "28"}, {"id": 7, "type": "short_answer", "skill": "computation", "question": "Calculate: 19 × 8", "difficulty": "medium", "explanation": "Multiply: 19×8=152", "needs_review": false, "correct_answer": "152"}, {"id": 8, "type": "short_answer", "skill": "computation", "question": "Calculate: 18 × 6", "difficulty": "medium", "explanation": "Multiply: 18×6=108", "needs_review": false, "correct_answer": "108"}, {"id": 9, "type": "short_answer", "skill": "computation", "question": "Calculate: 6 × 19", "difficulty": "medium", "explanation": "Multiply: 6×19=114", "needs_review": false, "correct_answer": "114"}, {"id": 10, "type": "short_answer", "skill": "computation", "question": "Calculate: 11 × 19", "difficulty": "medium", "explanation": "Multiply: 11×19=209", "needs_review": false, "correct_answer": "209"}, {"id": 11, "type": "short_answer", "skill": "computation", "question": "Calculate: 12 × 18", "difficulty": "medium", "explanation": "Multiply: 12×18=216", "needs_review": false, "correct_answer": "216"}, {"id": 12, "type": "short_answer", "skill": "computation", "question": "Calculate: 10 × 13", "difficulty": "medium", "explanation": "Multiply: 10×13=130", "needs_review": false, "correct_answer": "130"}]