A bag of rice weighs 25 kg. I used it for the first time (1/5). The remaining (1/4) was used for the second time. How many kilograms did you use the second time?
一袋大米重25千克．第一次用去了(1/5)．第二次用去了余下的(1/4)．第二次用去了多少千克？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">25 * (4/5) * (1/4)</gadget>
<output>5</output>

<result>5</result>