A book has 280 pages in total. Xiao Ming read 60 pages on the first day, which is 80% of the second day. How many pages are left?
一本书共有280页，小明第一天看了60页，是第二天的80%．还剩下多少页没看？
<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">60 / (4/5)</gadget>
<output>75</output>

<gadget id="calculator">280 - 60 - 75</gadget>
<output>145</output>

<result>145</result>