I have 580 stamps, 20 less than my brother's three times, how many stamps does my brother have?
我有580张邮票，比哥哥的3倍少20张，哥哥有多少张邮票？
<gadget id="calculator">580 + 20</gadget>
<output>600</output>

<gadget id="calculator">600 / 3</gadget>
<output>200</output>

<result>200</result>