Materials for the class

Short pieces of rope cut previously by the teacher (each piece has to measure a decimeter). Black or red marker to write on the piece of rope.

Layout of the classroom

The room should be empty. You can use the yard, if it’s sunny.

Phase 1

The teacher explains the children that each piece of rope (every child has one) has to become a caterpillar: it is necessary to draw eye and mouth of the caterpillar and, the most important thing, its segments. Its name will be “Decimeter Caterpillar” and its body will be divided into 10 segments that children have to draw, always with the same distance, on the rope (10 segments, each one measures 1 centimeter).

Alternately every child will play the role of the prince/princess, while the other school mates will play the role of the caterpillars. The teacher will play the role of the King/Queen that pose challenges to the prince/princess.

Phase 2

The teacher tells a tale about a prince/princess that wants to marry a princess/prince, but he/she has first to overcome some obstacles: he/she has to measure length of objects and living beings and distances. He/she doesn’t know how to do that, but he/she sees a caterpillar in the garden and decides to ask him for help.

The King/Queen gives some objects and distances to measure and the children, using their “Decimeter Caterpillars”, will give the exact answer in decimeters and centimeters.

Phase 3

Examples of questions that the teacher can pose:

– how tall is the table? (if the activity is in class)

– how large is the log of the tree? (if the activity is outside)

– how large is the door?

– how tall is the yard fence?

Phase 4

Then the teacher will explain the rule, using a true ruler.