Inhibiting the view of the header rows and the formula bar will tone down the “this is an Excel sheet, wander around and do whatever you like” mindset and keep users in the working area.

Click on it and pull the formula down ... you can calculate the square root using the SQRT function. Read: How to calculate the area of a Rectangle, Triangle or Circle in Excel.

With just a little work, I turned an Excel sheet into a modifiable piece of graph paper. The trick is to square up the cells ... Select the entire worksheet (or the area you want to resemble ...