A number is increased by 100, then reduced by 5 times, and then subtracted by 40 to get 30. What is the number?
一个数增加100，然后缩小5倍，再减去40，得30，这个数是多少．
<gadget id="calculator">30 + 40</gadget>
<output>70</output>

<gadget id="calculator">70 * 5</gadget>
<output>350</output>

<gadget id="calculator">350 - 100</gadget>
<output>250</output>

<result>250</result>