When a student was doing a calculation problem, the last step should be divided by 20, but 20 was added by mistake, so the wrong result was 180. What is the correct number for this calculation problem?
有一个学生在做计算题时，最后一步应当除以20，但却错误地加上20，因而得到错误的结果是180．请问这道计算题的正确得数应是多少．
<gadget id="calculator">180 - 20</gadget>
<output>160</output>

<gadget id="calculator">160 / 20</gadget>
<output>8</output>

<result>8</result>