Age:
6 years old

Aims:
To compose and decompose numbers;
To understand different uses of the number and identifying numbers in the context of everyday;
To reason mathematically, formulating and testing conjectures, explaining processes and ideas and justifying results;
To communicate orally and in writing, using the natural language and mathematical language, interpreting, expressing and discussing results, processes and mathematical ideas

Materials: Plastic bottle tops for counting, sheets of waxed paper and markers.
Introduction: - Presentation of the task to the class (10 minutes); - Hand out the material; - Explanation of some concepts for understanding the problem; - Exploration of the task by the students (30 minutes)
Task: Célia and Simon are saving money to buy a book. When they have a coin of 1 €, they put it in a box. They already have got seven coins there. How many coins could every child have put there?
Main part: - Presentation of the problem made by students; - Discussion of the task in the group (40 minutes) - Summary and final systematization of the content (10 minutes)
Roundup: Students must solve the task in an independent way but supervised by the teacher; thus, students will be the builders of their own learning

Observations:
This activity is done over 2 mornings and the children have had to have worked on decomposing smaller numbers in previous classes.