JV has done quite a bit of square root over last year. This year he picked up the peg board and promptly proved he couldn’t remember how to work it out even with the materials. A quick reminder was helpful. Another day or two of just working it out on the board bought us to a brief reminder of the written mathematical approach. He checked his previous work using the written approach and the board. It is all coming back. Hurray.
UPDATE: Here is a lesson learned about being able to write (not just speak) what you are doing in with a material.