Metric vernier calipers

The main scale on the bar is graduated in millimeters, and every main division is numbered. Each numbered division has a value of 10 millimeters; for example, #1 represents 10 mm, # 2 represents 20 mm, etc. There are 50 graduations on the sliding jaw vernier scale, with every fifth one being numbered. These 50 occupy the same space as 49 graduations on the main scale (49mm). Therefore 1 vernier division= =0.98mm
The difference between 1 main scale division and 1 vernier scale division=1-0.98=0.02mm.