Huufff……what a week!!! This couple week we teach our students the 3 dimensional (3D) shapes. Last week the focus was the characteristics of various 3D shapes (you know…… rectangular prism, cylinder, sphere, pyramid, etc). Luckily our students (and especially for ME….he3X) understood the characteristics well. It was easy for them to see that rectangular prism has 6 sides (sisi), 8 vertices (titik sudut), and 12 edges (rusuk). Or that a square pyramid has 5 sides, 8 edges, 4 vertices, AND 1 apex. Unfortunately that part was the easy one compared to what we teach this week.
This week we teach the concept of volume and how to measure the volume of a cube and rectangular prism. The students already understand that there are three components in every 3D shapes, which is Length (panjang), Width (lebar), and Height (tinggi). In a matter of minutes they understand that volume is the amount of liquid a certain shape can hold. After this we provide a cube made of several centicubes (that small yellow cubes thingy…if you don’t understand please look at the pictures) on every tables and ask them “How do you think we can measure the volume of the cube?” Now from this activity we can see which students have good spatial ability and the ones that need to develop theirs. The ones with good spatial ability only take a couple of minutes to realize that measuring the volume of the cube is by multiplying all the dimensions (length, width, and height) just like measuring the area on 2D shapes.. For these students we give a hands-on activity. They have to measure the volume of several items that we provided for them (see pictures)
Now for those who at loss (sigh……..luckily not many of them) we gather them together on a table and explain them step by step. I know what you thinking….how hard can it be to teach the students that Length x Width x Height equals Volume, right…??? Well….it’s true if you using inductive way of teaching, meaning you tell them yourself the formula. However in SGJ we teach our students deductively, meaning we teach in such a way that the students come to the conclusion that Volume = Length x Width x Height. Now back on the matter at hands….using centicubes I make a 2 x 2 x 2 cube and then ask them how many dimensions are there in the cube (again….see picture…and no, I wasn’t sleeping…) All of them answer correctly. Then I ask them this question “if this cube is a bucket and I fill it with water, what shape do you think the water will make?” again all of them answer correctly. My next question is “what are the length, width and height of the water inside the cube?” at this point they begin to see the connection and write the answers right away. Actually it would be better if during this activity we use a container and water as a tool but at that time we don’t have a container. It’s tiring and time consuming teaching this way but seeing the smile on our student’s faces and the joy they have when they are able to solve the problems makes it all worthwhile, don’t you think??? Well then this is our way of teaching volume to students. Feel free to drop us your comments or even suggestions on how to teach this topic creatively, OK???