Mr. Li spent 24.28 yuan on math reference books and 23.72 yuan on Chinese reference books. He paid the salesperson 50 yuan. How much should he get back? (calculated in two ways)
李老师买数学参考书用了24.28元，买语文参考书用了23.72元，他付给售货员50元，应找回多少钱？(用两种方法计算)
<gadget id="calculator">24.28 + 23.72</gadget>
<output>48</output>

<gadget id="calculator">50 - 48</gadget>
<output>2</output>

<result>2</result>