What is the difference if (1/4) is subtracted from 28?
28减去它的(1/4)，差是多少？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">28 * (1/4)</gadget>
<output>7</output>

<gadget id="calculator">28 - 7</gadget>
<output>21</output>

<result>21</result>