A book has 40 pages. Xiao Ming reads (1/8) on the first day and (4/8) on the second day. What percentage of the book did he read? How many pages are left?
一本书有40页，小明第一天看了(1/8)，第二天看了(4/8)，他一共看了几分之几？还剩多少页没看？
<gadget id="calculator">5 / 8</gadget>
<output>5/8 = around 0.625</output>

<gadget id="calculator">1 - (5/8)</gadget>
<output>3/8 = around 0.375</output>

<gadget id="calculator">40 * (3/8)</gadget>
<output>15</output>

<result>15</result>