Reading a micrometer takes practice.
If you think of the lines on the Sleeve as dollars and quarters,
the lines on the Thimble represent "pennies" or cents.
As the thimble rotates, you add those pennies to the dollars and quarters
O.K. so now we know how to read a micrometer! We just need some practice. In the picture below, the Sleeve shows 3 dollars and one quarter (25 cents). The Thimble shows one penny. To calculate this reading we add 3 dollars plus 1 quarter plus 1 penny. The actual measurement is .326 inches.
See if you can calculate the measurement below
Reading a micrometer gets easier with practice.
Here are some practice pages.