My older son left some of the work from his math club on the kitchen table and one of the problems looked like it would be a nice challenge for my younger son.

What I like listening to my son here is the struggle he has searching for the words to describe what he’s seeing with the numbers. Finding the right way to describe what you are seeing / doing is an important piece of learning math.

The problem challenges you to fill in the digits of a number puzzle. Here’s his initial reaction to the problem until we were interrupted by a phone call!):

So, there was actually no one there when I answered, so we moved on! I like the way he winds his way to the solution. The one little trick in the problem – that the letter O didn’t have to be a unique number – I left for the middle school kids. There was enough here to keep track of for a 4th grader.