(7/10) minus (2/10), what is the difference?
(7/10)减(2/10)，差是多少？
<gadget id="calculator">7 / 10</gadget>
<output>7/10 = around 0.7</output>

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

<gadget id="calculator">(7/10) - (1/5)</gadget>
<output>1/2 = around 0.5</output>

<result>1/2 = around 0.5</result>