If you buy 10 kilograms of rice, you need to pay 22.5 yuan, and how much you need to pay for 5.5 kilograms of rice.
买10千克大米需付22.5元，买5.5千克大米需付多少元．
<gadget id="calculator">22.5 / 10</gadget>
<output>2.25</output>

<gadget id="calculator">2.25 * 5.5</gadget>
<output>12.375</output>

<result>12.375</result>