In a customary micrometer, what does each number on the sleeve represent?

In a customary micrometer, each number on the sleeve typically represents a specific increment of measurement along the micrometer's scale, which is commonly expressed in inches. In this case, each number on the sleeve corresponds to a gradual increase in measurement, specifically at intervals of 0.100 inches.

For example, when the sleeve shows the number "1," it indicates a measurement of one hundred thousandths of an inch (0.100"). As the numbers increase sequentially, they continue to represent increments of 0.100". Therefore, using this understanding, the choice indicating 0.100" accurately reflects what each number on the sleeve represents in terms of measurement on a customary micrometer.