Xiao Ming did calculation problems. He did half of the total number on the first day, the remaining half on the second day, and 5 problems on the third day. He just finished all of them. How many calculation problems did Xiao Ming do in total?
小明做计算题，第一天做了总数的一半，第二天做了剩下的一半，第三天做了5个题，正好全部做完，小明一共做了多少个计算题．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(1/2) * (1/2)</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 - (1/2) - (1/4)</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">5 / (1/4)</gadget>
<output>20</output>

<result>20</result>