((2/5)+(1/6)-(2/15))*30.
((2/5)+(1/6)-(2/15))*30．
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">2 / 15</gadget>
<output>2/15 = around 0.133333</output>

<gadget id="calculator">(1/6) - (2/15)</gadget>
<output>1/30 = around 0.033333</output>

<gadget id="calculator">(2/5) + (1/30)</gadget>
<output>13/30 = around 0.433333</output>

<gadget id="calculator">(13/30) * 30</gadget>
<output>13</output>

<result>13</result>