Find the law and fill in the numbers: (1/20), (1/10), how much, (2/5), (4/5).
找规律填数：(1/20)，(1/10)，多少，(2/5)，(4/5)．
<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">(1/10) * 2</gadget>
<output>1/5 = around 0.2</output>

<result>1/5 = around 0.2</result>