Jayati Kaushik and Sindhu Sreedevi
Often when students are taught about volume, they are overwhelmed by formulas and calculations even if the formula is just l × b × h; and the concept of what they are calculating or why they are doing it or whether it has any significance whatsoever is lost to them. Thus the process of calculating volume becomes nothing more than a mundane exercise in multiplication. A successful lesson in volume must leave students with a clear idea of what volume is – it is not capacity; a 100ml bottle usually has higher volume; capacity is the amount of substance that can be contained by the vessel, but volume is the amount of space occupied by the solid. They must have an understanding of the parameters that affect volume and finally be able to calculate volume using the correct units and formulae.
Objective: To understand the difference between capacity and volume.
This is much better done through a discussion of how when we buy a 1L bottle of cold drink it is not filled up to the brim. However it occupies a certain amount of space in the fridge where you cannot put anything else. That space that it takes up is the volume but the amount of the stuff in it is its capacity.
As teachers, it is important for us to understand that children have an intuitive idea of measurement. Building upon this idea will facilitate their learning. Also, the idea of volume is close to real-life experience and therefore the need to direct the learning along the right path or appropriate method is important. Thus, posing a question from their natural routine will facilitate the learning. This specifically helps in making students understand better.
Any good situation that highlights the need for measuring volume, (one of my favourite examples to use is which cup gives you more juice) is good enough to pique interest in the idea of measuring volumes. Once the need for measuring volume is established, we can ask how this concept can be developed.
Jayati Kaushik is a BSc student doing a triple major course in mathematics, statistics, and economics. She is doing her term paper on teaching mathematics and has limited teaching experience mostly helping fellow classmates, juniors and cousins. She may be reached at firstname.lastname@example.org.
Sindhu Sreedevi has been a mathematics teacher and has specialized in learning assessment for the last nine years during which she has had opportunities to learn the practical aspects of teaching, learning, and assessment processes. She has also been part of the large scale assessment in Azim Premji Foundation. She can be reached at email@example.com.