Xiaohong bought a schoolbag for 50 yuan, and Aunt Wang in the store got back 27 yuan. How much is this schoolbag?
小红拿50元买一个书包，商店王阿姨找回了27元，这个书包多少元？
<gadget id="calculator">50 - 27</gadget>
<output>23</output>

<result>23</result>