Subtract 4 (1/20) from (8/20). What was the result?
从(8/20)里面减去4个(1/20)．结果是多少？
<gadget id="calculator">8 / 20</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 / 20</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">(1/20) * 4</gadget>
<output>1/5 = around 0.2</output>

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

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