1. Read the smallest division on the Vernier scale that coincides exactly with a main scale division. This is called the Vernier division.
2. Note the number of Vernier divisions that coincide with one main scale division. This number is typically either 10, 20, 50, or 100.
3. The least count (LC) of the Vernier scale is then calculated by dividing the smallest main scale division by the number of Vernier divisions that coincide with it.
4. Express the least count using proper units, such as millimeters (mm), centimeters (cm), or other relevant units.
Here's the formula to calculate the least count:
LC = (Smallest main scale division) / (Number of Vernier divisions coinciding with it)
Remember that the least count represents the smallest measurement that can be made using the Vernier scale and the main scale. It provides the precision of the measuring instrument.