E2.1 Choose and use non-standard units appropriately to measure lengths, and describe the inverse relationship between the size of a unit and the number of units needed.
Activity 1: Conservation of Length of the Same Object - I Measure with…
Goal
This activity supports students to develop the concept of conservation of the length such that the length of an object remains the same, regardless of the unit used to measure it
Material (per team of two students)
- domino box
- pencil
- 20 large paper clips
Instructions
Place students in teams of two.
Give each team a skewer, a domino, a pencil and a paper clip.
Have students measure the length of a desk with the domino.
Ask them to measure the length of the same desk again, this time with a paper clip.
Ask the following questions:
- How could the length of the desk be measured with a single pencil?
- How can you measure the length of the desk with the width of your thumb?
- Will the measurement of the length of the desk be larger in pencils or in thumb widths? How do you know?
- What is the measurement of the desk in pencils?
- What is the measurement of the desk in thumb widths?
- Is the desk larger when measured in pencils? How do you know this?
Have students measure the length of their forearm with :
- the width of their thumb;
- a sharpened pencil;
- a paper clip.
Review with the class that no matter what unit is used, the length of an object does not change.
Source: translated from L'@telier - Ressources pédagogiques en ligne (atelier.on.ca).
Activity 2: One, Two, Three, Jump!
Summary
In this activity, children measure the length of their jump using different objects and compare the results.
Material
- different objects that can be used as a benchmark object (for example, shoe, book, pencil, paintbrush, cube)
- masking tape
- sheet of paper (one per pair)
- interlocking cubes
Instructions
Ask children to form teams of two and have each team choose a benchmark from those provided or prepare a benchmark using connecting cubes.
Draw a starting line on the floor with masking tape and have the children take turns jumping from the starting line and measuring the length of their jump with the benchmark.
To measure the jump, have the children do the following:
- the student who jumps, places their heels on the starting line and then performs the jump;
- the student who measures, draws a horizontal line where the heels of the student who jumped landed;
- the student who jumped, measures their jump using the benchmark chosen by the team and writes the result in drawings on a sheet.
Facilitate a discussion to have students compare comparing each other's results. Ask questions such as:
- How long is your jump? How do you know?
- If you were to use another benchmark, would you get the same result? Justify your answer.
- Sophie and Jasmin used the same benchmark, but they got different results. Why?
Source: translated from Guide d’enseignement efficace des mathématiques, de la maternelle à la 3e année, Mesure, p. 120.
Activity 3: Measuring with a Personal Ruler
Goal
In this activity students are supported to transition from the use of non-standard to standard units.
Material
- several strips of paper of equal length and of two different colours (interlocking blocks of two colours could also be used.)
- a few strips of cardboard about 40 cm long and 3 cm wide
- Create a ruler by gluing the strips of paper next to each other on a strip of cardboard, alternating colours as shown in the following illustration.
- Using the constructed ruler, measure the length of various common objects and complete the following table.
Name of the Object
What is Measured: Length, Width, Height, Distance
Number of Small Coloured Bands
Example: my yellow pencil
length
5
Source: translated from L'@telier - Ressources pédagogiques en ligne (atelier.on.ca).