A book has 320 pages. Xiao Ming reads 20 pages a day for the first 10 days, and plans to read the rest 6 pages a day. How many days will it take to finish reading them all?
一本书有320页，小明前10天每天看20页，剩下的他准备每天看6页，那么还要多少天才能全部看完？
<gadget id="calculator">20 * 10</gadget>
<output>200</output>

<gadget id="calculator">320 - 200</gadget>
<output>120</output>

<gadget id="calculator">120 / 6</gadget>
<output>20</output>

<result>20</result>