This concept behind this question is easy to grasp. Hence, when I first asked my P3 students to attempt this question, I thought they would usually get it right. How very wrong I was!
While the concept is easy, the technique of handling this question may somehow be too challenging for some P3 students. There are simply too many magnets to compare! And they do not know how to start to compare them!
Most adults when facing such situations of teaching the children, they will usually start to teach these children their methods of comparisons. This was the mistake that I had made previously. As I have found out, such methods may not stick too well with the children especially with lack of explicit consistent practice (That is probably one of the reasons why children don’t usually remember the model answers in Maths problem sums).
So now, the first question that I usually ask the children is “Which magnet is the first one you see in the diagram?” From there, we will start to explore the second magnet for comparison, if it is a good choice for comparsion and etc.
As the children get comfortable with the question, it will be good if we can vary the question in different ways:
1) Arrange the 4 magnets in the magnetic strength in increasing order.
2) Move one or two of the magnets to different heights and see if the conclusion is different.
Isn’t Science fun and with unlimited possibilities to learn?