Teaching Square Roots to a Five Year Old

Dan Lewis:

A week or so ago, we gave my five year old son a little solar powered pocket calculator to play with. He explored the key pad and it didn’t take long before he had a question we didn’t really know how to answer. He saw the square root symbol and wanted to know what it was.
We — adults, generally — understand them, at least in a cursory way. The square root of 4 is 2, or 9 is 3, of 16 is 4, etc. until probably 100 or 144. But we learned it a long time ago, and we probably can’t remember how we learned it. And almost certainly, we learned the concept well after preschool. So not only do we not know how to teach the concept generally, but we certainly aren’t good at teaching it to people who are much, much younger than typically learn it.
But five year olds can be persistent so I gave it a go. I don’t know how much he understands the concept, but my son definitely gets some of it.