Xiao Ming reads a 180-page "Happy Dictionary", and reads an average of 20 pages a day in the first 3 days, and 24 pages a day for the rest. How many days will it take to finish this book?
小明看一本180页的《开心辞典》，前3天平均每天看20页，余下的每天看24页，看完这本书还要多少天？
<gadget id="calculator">20 * 3</gadget>
<output>60</output>

<gadget id="calculator">180 - 60</gadget>
<output>120</output>

<gadget id="calculator">120 / 24</gadget>
<output>5</output>

<result>5</result>