Measurement with a caliper is done using a ruler. Having spread the leg of the calipers slightly larger than the measured size, lightly tapping on the workpiece to be processed or on any other solid object, bring their ends closer so that they touch the outer surfaces of the part. Then this solution of the legs is transferred to a measuring ruler.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.