(28*15+380)*5.
(28*15+380)*5．
<gadget id="calculator">28 * 15</gadget>
<output>420</output>

<gadget id="calculator">420 + 380</gadget>
<output>800</output>

<gadget id="calculator">800 * 5</gadget>
<output>4_000</output>

<result>4_000</result>