There are 240 building blocks, yellow accounted for (1/5), red accounted for (1/4), how many more red blocks than yellow blocks.
有积木240块，黄色占(1/5)，红色占(1/4)，红色积木比黄色积木多多少块．
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/4) - (1/5)</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">240 * (1/20)</gadget>
<output>12</output>

<result>12</result>