Experiences

We measure the perimeters of figures

Aleksandra Pilc

Poland

Primary school

Maths

Teaching in class

Direct

The topics that seem to be simple and easy to understand, which made my pupils many difficulties were figures’ circuits. I decided to show to students outside the classroom what is the perimeter of figure, how to measure it and why. I divided the class into groups of three. We left the school building and then I told my pupils which objects we will be dealing with. We measured: place behind the school so-called terrace, basketball court, football field, run-up for long jump and fenced playground, which is located on the school area. Each team had ruler tape, pen and paper. Their task was to measure the circuits of all these objects. To avoid confusion, I set the order in which each group made measurements. Division into triple teams was intentional: two people were engaged in the measurements and the third wrote down the results. The first four areas were rectangular and students immediately noticed that it is sufficient to measure only the length of the adjacent edges and multiply it by two. It was a little bit problem with the playground because it is in the shape of a pentagon. As I watched them at work, I noticed that perform tasks in different ways. Some precisely added to each 3m length 56 cm (just because that was the maximum length of their scoops) and others smarter, marking the whole e.g. 3m + 3m +3 m and at the end the last 27cm. When all the teams finished we compared their measurements, and of course everyone was different, but the differences were of a few centimeters. Through this exercise, students understood how to count circuit and most of them for the first time had the opportunity to use the ruler tape which made them great fun.