This unit begins with having students use their bodies to measure the area of different shapes drawn on the floor. Understanding of area is developed through using non-standard units (e.g. beans, counters and blocks) to measure the area of objects in the classroom.
Non-standard units are objects which are used because they are known to students and are readily available, for example, paces for length, books for area, and cups for volume. Non-standard units introduce the students to the idea that units are repeated and counted in order to provide a measure of an attribute of an object. Therefore, students should be provided with many opportunities to measure using these kinds of non-standard units. For example, the width of the desk is 4 handspans.
Non-standard units introduce most of the principles associated with measurement:
Prior to introducing standard units, students need to realise that non-standard units tend to be personal and are not the most suitable for communication. For example, one student's hands will be smaller than another's, so measuring using hand span is not always useful or accurate.
Covering surfaces with a single unit should lead to discussion about which shapes that tessellate, and are therefore useful for covering surfaces. For example, rectangles and squares tessellate the plane, whilst circles do not. Tessellating with non-standard units establishes the need to cover surfaces without leaving gaps and without overlapping. It also demonstrates the advantages of using arrays that can be readily counted by using multiplication, for example, 3 rows of 6 tiles gives an area of 18 tiles.
From the earliest of these experiences, students should be encouraged to estimate. Initially these estimates may be no more than guesses, but estimating involves the students in developing a sense of the size of the unit. As everyday life involves estimating at least as frequently as finding exact measures, the skill of estimating is important.
At this stage students can also be introduced to the appropriateness of units of measure. For example, a hand is more appropriate than a finger tip for measuring the area of a desktop.
The learning opportunities in this unit can be differentiated by providing or removing support to students and by varying the task requirements. Ways to differentiate include:
The context for this unit can be adapted to suit the interests and experiences of your students. For example, in session 1 you could draw outlines of characters from a book you are reading the class. Similarly, for other activities, both the shapes being measured and the units being used to measure them could be chosen to appeal to your students.
Te reo Māori kupu such as ine (measure), āhua (shape), and tatau (count) could be introduced in this unit and used throughout other mathematical learning. You could also encourage students, who speak a language other than English at home, to share the words related to measurement that they use at home.
Today we introduce non-standard measures and use our bodies as measuring tools. Prior to this lesson, use tape or chalk to mark out several large areas of different shapes on the floor.
These sessions explore the use of non-standard measures and compare areas using non-standard measuring units.
Over the following days set up non-standard measuring tasks. For each task have students estimate, measure and then compare their results with others to order areas. You could explore each of these tasks as a whole class, or set them up as stations to be explored by groups of students across a few sessions. Consider starting and ending each session with a review of the tasks completed at the stations (e.g. what did you do? What was hard to measure? What was most enjoyable? Did you find any measurements surprising?). Roam and identify any misconceptions demonstrated in learning, and use these as the base for planning your review and/or targeted whole-class/small-group sessions. During this part of the unit, you should also consider any links that could be made between tasks and students' interests, cultural backgrounds, and learning in other curriculum areas (e.g. we have been reading about the stars of Matariki, can we use stars to cover this area? People fly kites at Matariki, can we use kites to cover this area?).
If you choose to use these tasks as stations, provide sufficient modelling of the task and instructions to ensure students can fully participate in the learning at each station. You could place a large graphic organiser (e.g. A3) at each station for groups of students to fill out.
Measuring tasks you could use include:
In this session students use their measuring skills to compare the areas of their feet and hands and find out which is larger.
Dear family and whānau,
This week at school we have been measuring the area of objects using our hands, beans and cardboard tiles. We have found out that it is important not to have any gaps or any overlaps when we are measuring.
At home this week your child is to use counters or their own choice of another object to measure the area of objects around the house. They can use pictures and numbers to record what they find out.
Printed from https://meaningfulmaths.nt.edu.au/mmws/nz/resource/great-cover at 8:44pm on the 26th February 2024