Puzzle Painting

This baby shower gift took at least 10 puzzles.  Sorting all the pieces was what took the most time.  Assembling the puzzle was only a couple of days.

The proud papa is working on a Ph.D in math, which is why I opted for numbers rather than letters.

 In the picture above I've sorted the pieces from dark to light green.  The idea is that the colors get lighter towards the middle of each square.

Puzzles are supposed to stimulate the mathematical parts of children's brains.  

I hope the baby likes it!