A story book, Xiao Ming wants to read it in 4 days. I read (1/2) of the whole book on the first day, (1/4) of the whole book on the second day, (1/8) of the whole book on the third day, and read this on the last day What fraction of the book?
一本故事书，小明想4天看完．第一天看了整本书的(1/2)，第二天看了整本书的(1/4)，第三天看了整本书的(1/8)，最后一天要看这本书的几分之几？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

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

<gadget id="calculator">1 / 8</gadget>
<output>1/8 = around 0.125</output>

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

<result>1/8 = around 0.125</result>