Fill in the blanks:
Pankaj measured the diameter of his little finger in _________________

Answer

To fill in the blank for the question "Pankaj measured the diameter of his little finger in _________________", we need to consider the appropriate units of measurement for the diameter.

### Step-by-Step Solution:

1. **Understanding the Measurement**: The diameter of an object is the distance across it through its center. In this case, we are measuring the diameter of Pankaj's little finger.

2. **Identifying Units of Measurement**: Common units used to measure small lengths include:
- Millimeters (mm)
- Centimeters (cm)
- Inches (in)

3. **Choosing the Right Unit**: Since the diameter of a little finger is relatively small, it is most appropriate to use millimeters or centimeters. However, inches can also be used depending on the context.

4. **Filling in the Blank**: Based on the common practice, we can fill in the blank with any of the suitable units. A common choice would be "millimeters" or "centimeters".

Thus, a complete answer could be:
"Pankaj measured the diameter of his little finger in **millimeters**."