A four-dollar roasted sweet potato weighs about 120 grams. The temperature of the roasted sweet potato should be controlled at about 200 to 250°C. The lower the temperature, the longer the time. When choosing sweet potatoes, choose fresh ones with a uniform shape. It is also slender and should not be too big, otherwise it will be difficult to cook. Wash it with water before baking, put it in the oven and preheat it at 200℃ for 15 minutes, then bake it at 250℃ for half an hour