Aims:
•  To understand fractions with the meanings: part-whole and the operator;

•  To reconstruct the unit from its parts;

•  To compare fractions and relate different representations of non-negative rational numbers.

Materials:
•  Presentation : worksheet ;

•  Exploration of the task: Cuisenaire bars;

•  Pupils' presentation: transparency film and a overhead projector.

Introduction:
•  Essential questions to be asked:

- Worksheet questions;

- How many equal parts like this (fractions) are required to get the unit? Which part of

the unit is this bar?

- How many decimals has got a unit?

- Half doesn't always correspond to the same bar. Why?

- How much is half of 10? And 4 of 10? - Can we get bars corresponding to half of each bar representing an odd number?

Main part:
- Split up the students in groups composed by two pupils each;

- Delivery of the materials (worksheet with the task and a sheet of paper A3);
- Silent reading of the task carried out by the groups;

- Exploration of the task undertaken by students;
- Each group presents on an A3 sheet of paper or on a transparency film what they propose as a resolution of the task;
- Discussion of the task to a large group;
- Systematization of the contents

Roundup:
Pupils should solve the task autonomously but under the supervision of the teachers. Thus, students will be the builders of their own learning since they are responsible for the acquisition of knowledge.