Naughty is reading 280 pages of an extra-curricular book these days. I read (3/7) of this book on the first day, and the number of pages I read on the second day is (2/3) of the first day. How many pages are left ?
淘气这几天在看一本课外书280页，第一天看了这本书的(3/7)，第二天看的页数是第一天的(2/3)，还剩多少页？
<gadget id="calculator">3 / 7</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">280 * (3/7)</gadget>
<output>120</output>

<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">280 * (3/7) * (2/3)</gadget>
<output>80</output>

<gadget id="calculator">280 - 120 - 80</gadget>
<output>80</output>

<result>80</result>