A piece of cloth, 50% is used for the first time, and the remaining 25% is used for the second time, leaving 25 meters. How many meters was the cloth originally?
一块布，第一次用去50%，第二次用去余下的25%，还剩25米．这块布原来有多少米？
<gadget id="calculator">50 / 100</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 - (1/2)</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(1/2) * (1/4)</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">1 - (1/2) - (1/8)</gadget>
<output>3/8 = around 0.375</output>

<gadget id="calculator">25 / (3/8)</gadget>
<output>200/3 = around 66.666667</output>

<result>200/3 = around 66.666667</result>