25% of 30 plus how much equals 10.
30的25%加上多少等于10．
<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">30 * (1/4)</gadget>
<output>15/2 = around 7.5</output>

<gadget id="calculator">10 - (15/2)</gadget>
<output>5/2 = around 2.5</output>

<result>5/2 = around 2.5</result>