If 20% of 250 kg of flour is eaten, and the remaining 20% is eaten, how many kilograms are eaten in total?
250千克面粉吃去20%，又吃去余下的20%，共吃去多少千克．
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">250 * (1/5)</gadget>
<output>50</output>

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

<gadget id="calculator">250 * (4/5) * (1/5)</gadget>
<output>40</output>

<gadget id="calculator">50 + 40</gadget>
<output>90</output>

<result>90</result>