Well,
First, we'd need to see what the problem is. Ā If it's an illustration with all of the dimensions of the rooms labeled, you can just write the area inside each room and then make a list of the values. Ā From there you can just add them up. Ā So making a table is just a more formal way of organizing your data. Ā The grids really do not offer much help in adding up the areas.