Aunt Wang brought 300 yuan to the supermarket to sell rice. The original unit price of a certain brand of rice was 4.8 yuan per kilogram. Aunt Wang went to the supermarket and found that this kind of rice was on sale, and the unit price was 4 yuan per kilogram. How many kilograms of rice can be bought in this way?
王阿姨带了300元钱到超市卖大米，某品牌的大米原来的单价是每千克4.8元．王阿姨到超市，发现这种大米正在促销，单价为每千克4元．这样可以多买多少千克大米？
<gadget id="calculator">300 / 4</gadget>
<output>75</output>

<gadget id="calculator">300 / 4.8</gadget>
<output>62.5</output>

<gadget id="calculator">75 - 62.5</gadget>
<output>12.5</output>

<result>12.5</result>