((1/6)+(2/5)-(1/2))*30.
((1/6)+(2/5)-(1/2))*30．
<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(2/5) - (1/2)</gadget>
<output>-1/10 = around -0.1</output>

<gadget id="calculator">(1/6) + (-1/10)</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">(1/15) * 30</gadget>
<output>2</output>

<result>2</result>