How much more is 7 times 3 than 1 times 3
3的7倍比3的1倍多多少
<gadget id="calculator">3 * 7</gadget>
<output>21</output>

<gadget id="calculator">3 * 1</gadget>
<output>3</output>

<gadget id="calculator">21 - 3</gadget>
<output>18</output>

<result>18</result>