There are 10 tenths of an inch in one inch. As one inch equals 2.54 centimeters, one tenth of an inch equals 0.254 centimeters.
In some contexts, a tenth of an inch can also be referred to as a line. That is, there are 10 lines in one inch. Inches represent just one of the commonly used units of length measurement in the Imperial system, which also includes the familiar measurement units of feet and miles. Twelve inches equal one foot. Three feet equal one yard, and 5,280 feet equal one mile. The Imperial measurement system also includes some less commonly used lengths such as furlongs and spans.