The power of subtraction

This is a really interesting idea conveyed by Sendhil Mullainathan. He talks about some work by Lydie Klotz's book Subtract.

Okay, so people come in the app, they see a grid and the grid has different colors. And so your job is when you click on a tile, it changes the color, it flips it. It's a little game. And what you want to do is you want to try to make the grid symmetric color wise. Okay. And you find that in about 12 flips, you can make it symmetric. And there's actually a much easier way to do it than 12. I think it's four or eight steps, much fewer. But when you do the 12, it's because you're looking to add colors to create symmetry. The way you do four is you remove colors to create symmetry. And Lydie's point in the book is that in many situations, we look to create good changes by addition. We rarely look to get to where we want to subtraction.