After Li Jun brought 20 stamps to Chen Hua, they both had the same number of stamps. It is known that Li Jun collected 320 stamps, how many stamps did Chen Hua collect?
李军拿来20张邮票给陈华后，两人邮票张数相等．已知李军收集邮票320张，陈华收集邮票多少张？
<gadget id="calculator">320 - 20 - 20</gadget>
<output>280</output>

<result>280</result>