1/(55-5*7)*(2/7).
1/(55-5*7)*(2/7)．
<gadget id="calculator">5 * 7</gadget>
<output>35</output>

<gadget id="calculator">55 - 35</gadget>
<output>20</output>

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

<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">(1/20) * (2/7)</gadget>
<output>1/70 = around 0.014286</output>

<result>1/70 = around 0.014286</result>