Workshop 4 : Geometry and shape

MEASUREMENT ( Selecting appropriate units and indirect comparison)

- In this entry, topic on measurement will be further explored, aiming in establishing a learning experience which introduce and extends the student's understanding the aspect of indirect comparison. In teaching the concept of measurement, teacher needs to address the difference between standard units and non standard units.Origo ( 2008) defines standard units as a set amount which is used to measure a quantity in which it is uniform and have been approved and acknowledged by a regulatory body. The examples are meter, centimeter or seconds.
-Heirdsfield ( 2011) comes out with a series of teaching sequence in which it serves as a guideline to a more effective teaching of measurement. Firstly, the teacher needs to get the students to identify the attribute to be measured, for instance getting the students to compare the perimeter of their class table with non standard measuring devices such as ice cream sticks, pins or paper tape.

The pictures above shows the non standard measurement devices namely paper tape, ice cream sticks and pins.

- Then, in doing the comparison, the students need to identify the most appropriate units in which they would used as to measure the perimeter of the table. Teacher should let the students to choose which measuring device would they use ( pins, ice cream stick or paper tape). However, the teacher should address that the smaller a measuring device holds, the measurement is more accurate. Let's say that if the teacher demands the most accurate measurement, then the students need to use the pins as it is the smallest amongst the others measuring devices.
- Schwartz (1995) claims that the children measure things based on individual purpose. Thus, in making learning experience more meaningful, teacher can come out with activities of making a portfolio, compiling the comparisons that they did so that they can show it to the families and friends later.

These two pictures demonstrates indirect comparison of the perimeter of the table with ice cream sticks and pins. In order to get the most accurate measurement of the comparison, pins is a better option compared to ice cream sticks.
* Tips : teacher can get the students to talk about the comparisons, for instance asking the students to describe what they did and what are the measuring devices that they used in this indirect comparison.

MAKING A MEASURING DEVICE

- Measuring device is an important element in this topic. Previously, we have been talking about factors to be consider in selecting the most appropriate units and indirect comparison in relation to standard and non standard. Thus, in this section, a further exploration on creating a meaningful learning experience addressing the topic of making our own measuring device will takes place.
- In establishing a learning experience to address this topic, firstly, teacher needs to provide the students with the materials. In this activities, several materials such as popcorn, cups and container ( see picture below) is needed.


The cups containing popcorn will dole out as 'measuring devices' in measuring the volume of other containers.






In measuring the volume of containers ( picture below), cups of popcorn is one of the ways that can be used. Firstly, teacher needs to set up the students in group of three. The teacher explains to the students what they should do. The students need to fill the cups with popcorn and then pour it to the container as to see how many cups of popcorn will occupy the container. Thus, the number of cups = the volume of the container.






The picture shows the process of occupying the containers with the popcorn using the cup provided.











*Teacher should note the students that when they finish pouring the first cup of popcorn into the container, they need to mark the level of the popcorn using a marker pen. This is to track down how many cups have the students pour. That marks will helps the students not to get confuse.



The marks put indicates that the container is able to occupy four cups of popcorn, which means that the volume of the container is approximately equals to four cups of popcorn. The cups of popcorn acts as a measuring device which manages to measure the capacity of the container. Thus, this activity does engage the students in making measuring device.

As presented above, that container, let's name it container A. Container A manages to occupy four cups of popcorn. Then, teacher gives the students a bigger container, container B. As to make the challenge more changeling, the students needs to measure the capacity of the container B ( how many cups can the container hold), without using the cups. The students will use container A as to get the volume of the container B.












Container A has become a new measuring device in which it can be used to measure the volume of container A. Asking the students to justify their measuring device and how it works in measuring container B is a good activities as it stimulus the students reasoning and critical thinking skills. The dialogue between the teacher and students may seem to appeared as below.

Teacher : can we use container A as to measure container B?
Student : Yes, we can do that. ( Pour the popcorn in container A to B). Two containers A equals to one container B.
Teacher : What about the quantity of cups? How many cups fits into container B?
Student : Container A equals to 4 cups of popcorn. Meanwhile, container B equals to 2 times container A. Thus, container B equals to 8 cups of popcorn.

The container A in this situation serves as a new measuring device that the students had created from the early process in which it equals to 4 cups of popcorn. Thus, this container can be used as to measure the volume of other big container namely container B.