Watch the video: Why does the ruler actually have a hole?
It belongs in every pencil case: the ruler. Measure, draw, fold – the practical tool is a real all-rounder. But why does the ruler actually have a hole? When they were still writing on slates in school, the hole was used to attach a piece of ribbon with a cloth. When slates were no longer used in class, the hole was given a new purpose: the rulers were hung on small hooks to create order. But the hooks are quickly abolished again. The reason: The risk of injury is too great. Today the holes have lost their use. Despite this, many rulers are still made with a hole.