An exercise book has 42 pages in total. Zhang Hui used 6 pages on the first day and the rest (1/3) on the second day. How many pages are left?
一本练习本共有42页，张惠第一天用了6页，第二天又用了剩下的(1/3)，还剩多少页．
<gadget id="calculator">42 - 6</gadget>
<output>36</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 - (1/3)</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">36 * (2/3)</gadget>
<output>24</output>

<result>24</result>