NYS requires students to use a grid slide to find the diameter of the field of view in the microscope, then remove the grid slide and estimate the size of a specimen in comparison. This practice worksheet reviews that skill. Specimens are not to scale!
This was time-consuming to create, hence the slightly higher price.
P.S. I have another great activity for this skill that I want to polish before uploading, but contact me if you're in need and I can post it as is.