Apples are 4.5 yuan per kilogram. Grandma Li bought 10.8 kilograms and paid 50 yuan. How much should I get back?
每千克苹果4.5元，李奶奶买了10.8千克，付了50元，应找回多少元？
<gadget id="calculator">4.5 * 10.8</gadget>
<output>48.6</output>

<gadget id="calculator">50 - 48.6</gadget>
<output>1.4</output>

<result>1.4</result>