Grandma asked Xiao Mo to go to the supermarket to buy rice. The original unit price of a certain brand of rice was 4.8 yuan per kilogram, and grandma prepared to buy 30 kilograms for Xiao Mo. Xiao Mo came to the supermarket and found that this kind of rice was on sale, and the unit price was 4.5 yuan per kilogram. How many kilograms of rice can be bought in this way?
奶奶让小莫去超市买大米．某品牌大米原来的单价是每千克4.8元，奶奶给小莫准备好买30千克的钱．小莫来到超市，发现这种大米正在促销，单价为每千克4.5元．这样可以多买多少千克大米？
<gadget id="calculator">30 / 4.5</gadget>
<output>6.666667</output>

<gadget id="calculator">4.8 * 6.666667</gadget>
<output>32.000002</output>

<gadget id="calculator">32.000002 - 30</gadget>
<output>2.000002</output>

<result>2.000002</result>