[{"id": 1, "type": "short_answer", "skill": "computation", "question": "Calculate: 35 + 15", "difficulty": "medium", "explanation": "Add systematically.", "needs_review": false, "correct_answer": "50"}, {"id": 2, "type": "multiple_choice", "skill": "properties", "options": ["Associative property", "Identity property", "Commutative 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: 4 × 14", "difficulty": "medium", "explanation": "Multiply: 4×14=56", "needs_review": false, "correct_answer": "56"}, {"id": 4, "type": "short_answer", "skill": "computation", "question": "Calculate: 15 × 6", "difficulty": "medium", "explanation": "Multiply: 15×6=90", "needs_review": false, "correct_answer": "90"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 3 × 7", "difficulty": "medium", "explanation": "Multiply: 3×7=21", "needs_review": false, "correct_answer": "21"}, {"id": 6, "type": "short_answer", "skill": "computation", "question": "Calculate: 20 × 10", "difficulty": "medium", "explanation": "Multiply: 20×10=200", "needs_review": false, "correct_answer": "200"}, {"id": 7, "type": "short_answer", "skill": "computation", "question": "Calculate: 5 × 20", "difficulty": "medium", "explanation": "Multiply: 5×20=100", "needs_review": false, "correct_answer": "100"}, {"id": 8, "type": "short_answer", "skill": "computation", "question": "Calculate: 15 × 11", "difficulty": "medium", "explanation": "Multiply: 15×11=165", "needs_review": false, "correct_answer": "165"}, {"id": 9, "type": "short_answer", "skill": "computation", "question": "Calculate: 8 × 16", "difficulty": "medium", "explanation": "Multiply: 8×16=128", "needs_review": false, "correct_answer": "128"}, {"id": 10, "type": "short_answer", "skill": "computation", "question": "Calculate: 14 × 13", "difficulty": "medium", "explanation": "Multiply: 14×13=182", "needs_review": false, "correct_answer": "182"}, {"id": 11, "type": "short_answer", "skill": "computation", "question": "Calculate: 6 × 16", "difficulty": "medium", "explanation": "Multiply: 6×16=96", "needs_review": false, "correct_answer": "96"}, {"id": 12, "type": "short_answer", "skill": "computation", "question": "Calculate: 15 × 13", "difficulty": "medium", "explanation": "Multiply: 15×13=195", "needs_review": false, "correct_answer": "195"}]