Shrimp is 21.5 yuan per kilogram, and fish is 11.4 yuan per kilogram. Mom bought 0.6 kg of shrimp and 1 kg of fish and paid 30 yuan, how much should I get back?
虾每千克21.5元，鱼每千克11.4元．妈妈买了0.6千克虾和1千克鱼，付出30元，应找回多少元．
<gadget id="calculator">21.5 * 0.6</gadget>
<output>12.9</output>

<gadget id="calculator">11.4 * 1</gadget>
<output>11.4</output>

<gadget id="calculator">12.9 + 11.4</gadget>
<output>24.3</output>

<gadget id="calculator">30 - 24.3</gadget>
<output>5.7</output>

<result>5.7</result>