How do you read a micrometer? Provide an example with at least 3 readings.

The 10 mm mark is visible, and one 0.5 mm mark is visible past 10 mm.
Main scale reading: $10.50 \text{ mm}$

The line aligns with 20.
Thimble scale reading: $20 \times 0.01 \text{ mm} = 0.20 \text{ mm}$

Total reading: $10.50 \text{ mm} + 0.20 \text{ mm} = \boxed{\text{10.70 mm}}$

2.

The 5 mm mark is visible, and one 0.5 mm mark is visible past 5 mm.
Main scale reading: $5.50 \text{ mm}$

The line aligns with 10.
Thimble scale reading: $10 \times 0.01 \text{ mm} = 0.10 \text{ mm}$

Total reading: $5.50 \text{ mm} + 0.10 \text{ mm} = \boxed{\text{5.60 mm}}$

3.

The 0 mm mark is visible, and one 0.5 mm mark is visible past 0 mm.
Main scale reading: $0.50 \text{ mm}$

The line aligns with 20.
Thimble scale reading: $20 \times 0.01 \text{ mm} = 0.20 \text{ mm}$

Total reading: $0.50 \text{ mm} + 0.20 \text{ mm} = \boxed{\text{0.70 mm}}$

4.

The 15 mm mark is visible, and one 0.5 mm mark is visible past 15 mm.
Main scale reading: $15.50 \text{ mm}$

The line aligns with 45.
Thimble scale reading: $45 \times 0.01 \text{ mm} = 0.45 \text{ mm}$

Total reading: $15.50 \text{ mm} + 0.45 \text{ mm} = \boxed{\text{15.95 mm}}$

5.

The 20 mm mark is visible, and one 0.5 mm mark is visible past 20 mm.
Main scale reading: $20.50 \text{ mm}$

The line aligns with 10.
Thimble scale reading: $10 \times 0.01 \text{ mm} = 0.10 \text{ mm}$

Total reading: $20.50 \text{ mm} + 0.10 \text{ mm} = \boxed{\text{20.60 mm}}$

6.

The 15 mm mark is visible, and one 0.5 mm mark is visible past 15 mm.
Main scale reading: $15.50 \text{ mm}$

The line aligns with 25.
Thimble scale reading: $25 \times 0.01 \text{ mm} = 0.25 \text{ mm}$

Total reading: $15.50 \text{ mm} + 0.25 \text{ mm} = \boxed{\text{15.75 mm}}$