Mom goes to buy 4 kilograms of apples and spends 21.2 yuan. Dad takes 100 yuan to buy 9 kilograms of the same apple. How much should I get back?
妈妈去买4千克苹果，用去21.2元钱，爸爸带100元钱，去买同样的苹果9千克，应该找回多少钱？
<gadget id="calculator">21.2 / 4</gadget>
<output>5.3</output>

<gadget id="calculator">5.3 * 9</gadget>
<output>47.7</output>

<gadget id="calculator">100 - 47.7</gadget>
<output>52.3</output>

<result>52.3</result>