Xiao Ming reads an 84-page book. He reads (1/4) of the whole book on the first day, and reads 30 pages on the second day. How many pages should he start from on the third day?
小明看一本84页的书，第一天看了全书的(1/4)，第二天看了30页，第三天应从多少页看起．
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">84 * (1/4)</gadget>
<output>21</output>

<gadget id="calculator">21 + 30 + 1</gadget>
<output>52</output>

<result>52</result>