Common Notion 5
The whole is greater than the part.
There is more here than it seems. This says that in our puzzle, the completed puzzle is always more than any combination of individual pieces (except all the pieces, which is a whole not a part). It also implies that when we have a part of a whole, there exists another part. In a 100 piece puzzle, if you remove 5 pieces, those 5 pieces are less than the whole 100, but it also implies there are 95 other pieces in addition to your 5.
Tool Practice
Use the applet to convince yourself of CN 5!
HINT: Use the sliders to adjust the size of the parts inside the large square, notice that the areas of the smaller rectangles will always be less than the area of the large square so long as you don't add all 4 rectangle together.