The unlimited way to eat chocolate is as follows:

Cut the chocolate with a knife at an angle of about 30 degrees. After cutting the chocolate, cut the right side of the top piece and cut the left side. Put one piece on the right, and put the right side on the left. At this time, you will find an extra piece. Cut out the extra piece, and the chocolate becomes the original whole piece again.

Principle

In fact, the cut chocolate blocks seem to fit together "seamlessly" on the surface. However, it is just because the slope of the oblique cutting is the same. In the end, The resulting rectangle is slightly shorter than the original rectangle.

The area of ??these missing "small sections" happens to be the area of ??the extra whole piece. It is impossible for the chocolate to increase out of thin air. All this is just a visual misalignment.