Recall the calculation for the FOV at high power. Estimate the size of a single cheek cell (at its widest point). One way to look at this is to estimate how many of these cells it would take to cross the entire diameter of the field of view. Then divide the FOV by the number of cells. Width of a single cheek cell =
FOVhighNumber of cells across diameter =

m

If you can include an explanation, it would be appreciated.