8.4/5/8*(5+5)*8=how much.
8.4/5/8*(5+5)*8=多少．
<gadget id="calculator">8.4 / 5 / 8</gadget>
<output>0.21</output>

<gadget id="calculator">5 + 5</gadget>
<output>10</output>

<gadget id="calculator">0.21 * 10 * 8</gadget>
<output>16.8</output>

<result>16.8</result>