((1/2)-((3/4)-(3/5)))/(7/10).
((1/2)-((3/4)-(3/5)))/(7/10)．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">(3/4) - (3/5)</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">(1/2) - (3/20)</gadget>
<output>7/20 = around 0.35</output>

<gadget id="calculator">7 / 10</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">(7/20) / (7/10)</gadget>
<output>1/2 = around 0.5</output>

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