Folding ruler has its scale numbers arranged so that when the ruler is folded up the lowest number section is on the bottom of the ruler, so that measurements can be made without parallax errors when the ruler is partially folded

摘要

Folding ruler (1) with numbers marked on a scale for distance measurement, whereby the number values are marked on one side (100) of the scale and increase in a first counting direction (12). The counting direction is chosen so that the lowest number values are covered when the ruler is completely folded up.