The ruler has a clear scale to measure length.

A series of marks or lines used for measuring or comparing.
The map has a scale.
Use the scale to check the weight.
The scale shows numbers.
a clear scale
map scale
weight scale
ruler
graduations
measure
The fish's shiny scale reflected the sunlight.

A hard, protective outer covering found on the bodies of certain animals, such as fish and reptiles.
A fish has many scales.
Each scale protects the fish.
The snake shed its old scale.
fish scale
reptile scale
shiny scale
plate
shield
covering
Please put the apples on the scale to weigh them.

A device used for weighing or measuring the weight of an object.
The scale showed my weight.
Use the kitchen scale for baking.
The scale is accurate.
on the scale
kitchen scale
digital scale
balance
weighing machine
spring scale