A right-to-left ruler is a type of ruler or measuring tool that is designed to be read from right to left instead of the traditional left-to-right orientation.
Lance right-to-left rulers have markings that start at the right-hand side of the ruler and increase in value as they move towards the left-hand side of the ruler. The numbers and measurements on a right-to-left ruler are also reversed from those on a left-to-right ruler, with the smallest values being located on the right-hand side and the largest values being located on the left-hand side.
In essence, a right-to-left ruler functions in the same way as a left-to-right ruler, but it is designed to be used in the opposite direction to accommodate the specific needs of right-to-left writing systems.