The Lego Ruler is buildable and you can build it together from scratch which could be fun for kids and even adults.
The Ruler builds into a 15cm to a 30cm ruler.
It is suitable for age 5 years and older
It has a Metric on the one side and Imperial on the other.
The Lego Pencil Box is so cool because you can stick almost any Lego stationery inside with a Lego plate so that the contents do not move around in your pencil box which also makes a less of a noise.