Xiaohua reads a book. He reads (3/8) of the whole book on the first day, and reads less (1/4) of the whole book on the second day than on the first day. What fraction of the book is left? look?
小华看一本书，第一天看了全书的(3/8)，第二天比第一天少看了全书的(1/4)，还剩下这本书的几分之几没有看？
<gadget id="calculator">3 / 8</gadget>
<output>3/8 = around 0.375</output>

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

<gadget id="calculator">(3/8) - (1/4)</gadget>
<output>1/8 = around 0.125</output>

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

<result>1/2 = around 0.5</result>