Answer
$0.537~ in$
Work Step by Step
We have $5$ numbered divisions on the barrel:
$5 \times 0.100~in = 0.500~in.$
We have $1$ small division on the barrel:
$1 \times 0.025~in= 0.025~in$
The head reading is $12$:
$12\times 0.001~in= 0.012~in$
Thus, the total measurement is:
$0.500+0.025+0.012=0.537~in$
