How many 240 are subtracted from 9000 to get 1800.
从9000里面减去多少个240，得1800．
<gadget id="calculator">9_000 - 1_800</gadget>
<output>7_200</output>

<gadget id="calculator">7_200 / 240</gadget>
<output>30</output>

<result>30</result>