For a rope, the full length (1/8) was used on the first day, and more (3/8) of the full length was used on the second day than on the first day, and the rest was used up on the third day. Please do the math, what fraction of the total length was used on the third day?
一根绳子，第一天用了全长的(1/8)，第二天比第一天多用了全长的(3/8)，剩下的第三天用完．请你算一算，第三天用了全长的几分之几？
<gadget id="calculator">1 / 8</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">3 / 8</gadget>
<output>3/8 = around 0.375</output>

<gadget id="calculator">(1/8) + (3/8)</gadget>
<output>1/2 = around 0.5</output>

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

<result>3/8 = around 0.375</result>