The little bear toy is 42 yuan each, and if you buy 6, you will pay 300 yuan. How much should I get back?
小熊玩具42元一个，买6个，付300元．应找回多少元？
<gadget id="calculator">42 * 6</gadget>
<output>252</output>

<gadget id="calculator">300 - 252</gadget>
<output>48</output>

<result>48</result>