Starting from Children's Day, Xiao Ming read 72 pages of books in the first 4 days. According to this calculation, how many pages can Xiao Ming read in total this month? (Solution with proportional knowledge)
从儿童节那天开始，小明前4天看了72页书，照这样计算，这个月小明一共可以看多少页书？(用比例知识解)
<gadget id="calculator">72 / 4</gadget>
<output>18</output>

<gadget id="calculator">1 / 30</gadget>
<output>1/30 = around 0.033333</output>

<gadget id="calculator">18 / (1/30)</gadget>
<output>540</output>

<result>540</result>