Using a graticule and micrometer

- Line up eyepiece graticule and the stage micrometer (like a ruler) - Each division on the stage micrometer is 0.1 mm long - At this magnification, 1 division on the stage micrometer = 4.5 divisions on the eyepiece graticule - To work out size of 1 division on the eye piece graticule, divide 0.1 by 4.5 (=0.022 mm)