A bag of flour weighs 25kg, and (1/5) is used for the first time, and the rest (1/4) is used for the second time, how many kilograms of flour are left?
一袋面粉重25kg，第一次用去(1/5)，第二次用去余下的(1/4)，还剩多少千克面粉？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

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

<gadget id="calculator">25 - 5</gadget>
<output>20</output>

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

<gadget id="calculator">20 * (1/4)</gadget>
<output>5</output>

<gadget id="calculator">25 - 5 - 5</gadget>
<output>15</output>

<result>15</result>