A story book has 81 pages, and Ding Ding has read 27 pages, what percentage of the pages did he not read?
一本故事书有81页，丁丁已经看了27页，没看的页数占全书的几分之几？
<gadget id="calculator">81 - 27</gadget>
<output>54</output>

<gadget id="calculator">54 / 81</gadget>
<output>2/3 = around 0.666667</output>

<result>2/3 = around 0.666667</result>