Flour is 2.4 kilograms per kilogram, and rice is 2.5 yuan per kilogram. Xiaohua bought 5 kilograms of flour and 5 kilograms of rice and paid 25 yuan. How much should I get back?
面粉每千克2.4千克，大米每千克2.5元，小华买面粉和大米各5千克，付出25元，应找回多少元？
<gadget id="calculator">2.4 * 5</gadget>
<output>12</output>

<gadget id="calculator">2.5 * 5</gadget>
<output>12.5</output>

<gadget id="calculator">12 + 12.5</gadget>
<output>24.5</output>

<gadget id="calculator">25 - 24.5</gadget>
<output>0.5</output>

<result>0.5</result>