Zero point ruler / Ruler

This design was conceptualized from people's habit of always starting from point '0' when using a ruler.
This is a ruler that displays numerical values starting from 0 in the left/right direction from any location pinpointed with a pen.
This is a rule that eliminates the need for separately calculating the numerical values since it will always start from 0 when drawing a line or measuring a measurement.

The point 0 is always located at the far left end of the existing ruler.
People continue to use it despite the inconvenience of the point 0 always being located at the far left end.

People use the existing ruler by calculating from the pint 5, 10 or 15 when they are not starting from the point 0, but this is also very inconvenient.