The school bought 5 footballs, each football is 70.5 yuan, and paid 400 yuan, how much should be recovered.
学校买了5个足球，每个足球70.5元，付出400元，应找回多少元．
<gadget id="calculator">5 * 70.5</gadget>
<output>352.5</output>

<gadget id="calculator">400 - 352.5</gadget>
<output>47.5</output>

<result>47.5</result>