What is Least count and how to calculate it

Hi,

Least count of a measuring instrument is the least value of physical quantity that can be measured accurately using the instrument. It may be calculated by dividing the main scale reading by the total number of small divisions between two main scale readings in case of linear scales.

For example,

Take a simple scale (length measuring instrument) of 15 cm. In this scale, you can see that the 1 cm is divided into 10 equal parts. Therefore, the least value it can measure is 1cm/10=0.1cm or 1mm which is least count of this instrument.

@ Prateeksha: Good!