(1/2)x-25%=10, x=how much.
(1/2)x-25%=10中，x=多少．
<gadget id="calculator">10 + 0.25</gadget>
<output>10.25</output>

<gadget id="calculator">10.25 * 2</gadget>
<output>20.5</output>

<result>20.5</result>