☆+☆+☆=12, ★+★+★=9, ☆+★=how much
☆+☆+☆=12，★+★+★=9，☆+★=多少
<gadget id="calculator">12 / 3</gadget>
<output>4</output>

<gadget id="calculator">9 / 3</gadget>
<output>3</output>

<gadget id="calculator">4 + 3</gadget>
<output>7</output>

<result>7</result>