Consistent motion R / Ruler

This ruler designed for solving out problems in using a small ruler is inspired by the fact that people usually press the ruler with fingers to fix it when using it, and is easily movable only with your fingers, along the existing path. It is designed to move the part of the ruler where a thumb touches along the side of it, by separating the parts meeting a thumb and a middle finger that are mainly used for pressing and fixing the ruler. Therefore, you can move the ruler easily, moving the other side of it, after pressing and fixing one side with fingers.