Experiences

Discover body around us

Zuzana Kuppeová

Slovakia

Lower Secondary School

Maths

Teaching in class

Direct

The thematic unit of Stereometry does not belong to the favorites thematic units in mathematics. Students have some knowledge of of it already from their elementary school studies. I use this fact to ensure they get familiar with the mathematical bodies from a different perspective as well. Most of them think that cube, cuboid, cylinder, cone and sphere ... exist only in mathematics. I try the students to befriend the bodies by looking around them and exploring their different specimen forms. Then we discuss how their day goes beginning from the morning of the day and where everywhere they can come into a contact with the bodies. Then the students divide themselves into groups that are formed by 4 students and have 20 minutes to write out as many things, objects, specimen of normal life in the shapes of cube, cuboid, cylinder, pyramid, cone and sphere. Of course, they must be identified correctly into the individual categories of the bodies. Then I collect these papers. After that one student comes from each group and reads out aloud the written answers of his or her group. Other students in the class count the number of correctly identified specimens. The winning group is rewarded by a grade. I have good experience in preparing this task as students use their fantasies. At the end they are often surprised by the volume of objects they discovered related to mathematics. Plus is also the fact, there are no examples to calculate.
The last part of the lesson is designed to set the homework. This time I divide the students into pairs. Each pair has to prepare a PowerPoint presentation on the bodies around us. Each presentation focuses on a different theme. E.g. bodies in sport, household, food, construction. Chefs look for bodies in their industry, waiters in theirs. One pair will prepare a presentation from a mathematical point of view, where there will be geometric objects in free parallel projection and the formulas for calculating their volume and surface areas. The presentation has a minimum of 6 slides dedicated to 6 geometric dimensional structures in which there are images used as examples of the subject. Each pair presents their presentation during the next class by demonstrating the topic in front of the class. Sometimes two lessons are needed for this task. At the same time I guide them to think of and eventually invent examples of what situations can be adapted for counting. Then the students are ready to compute examples. These two activities really help them get into the task of calculating the spatial volume and surface areas of geometric figures and in particular, the practical application that is visible in the examples.