How many (1/10) are subtracted consecutively from (2/5) to get 0.
从(2/5)里面连续减去多少个(1/10)后得数为0．
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">(2/5) / (1/10)</gadget>
<output>4</output>

<result>4</result>