A book has 400 pages. I read the whole book (1/8) on the first day, and the rest (1/7) on the second day. How many pages should I read on the third day?
一本书400页，第一天看了全书的(1/8)，第二天看了剩下的(1/7)，第三天应从第多少页看起．
<gadget id="calculator">1 / 8</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">400 * (1/8)</gadget>
<output>50</output>

<gadget id="calculator">1 - (1/8)</gadget>
<output>7/8 = around 0.875</output>

<gadget id="calculator">1 / 7</gadget>
<output>1/7 = around 0.142857</output>

<gadget id="calculator">400 * (7/8) * (1/7)</gadget>
<output>50</output>

<gadget id="calculator">50 + 50 + 1</gadget>
<output>101</output>

<result>101</result>