120/(4*3.9+(7.45-3.05))*3.
120/(4*3.9+(7.45-3.05))*3．
<gadget id="calculator">4 * 3.9</gadget>
<output>15.6</output>

<gadget id="calculator">7.45 - 3.05</gadget>
<output>4.4</output>

<gadget id="calculator">15.6 + 4.4</gadget>
<output>20</output>

<gadget id="calculator">120 / 20</gadget>
<output>6</output>

<gadget id="calculator">6 * 3</gadget>
<output>18</output>

<result>18</result>