Fold a piece of square paper in half, and then fold it in half again. Do this several times in a row, and write down the number of rectangular pieces when it is folded in half 4 times.
把一张正方形的纸对折，再对折，这样连续几次，写出对折了4次时长方形的块数是多少块．
<gadget id="calculator">2 * 2 * 2 * 2</gadget>
<output>16</output>

<result>16</result>