Plutification

As Pipi Longstocking found out, 'plutification' is not always very easy.

Recently, one of my Ethiopian students sent me a link showing the traditional Ethiopian way of multiplication. The approach is very different from how multiplication is done in the West, although both methods are mathematically equally valid.

To find out how Ethiopians do multiplication, click here.

No doubt you are wondering why an MSc student on one of my language courses would send me a link about mathematics. The reason is Henry's homework.

Henry had some difficulties with subtraction, for example, 33 minus 17. So I tried to show him the way I had been taught, i.e. "ten to the top, one to the bottom." But he refused to accept this method as he had been taught a different way at school, moving tens from one column to another. This deadlock led to Henry's mother being asked for her expert opinion, she being a maths graduate. H-M agreed with Henry.

So, what does one do when one disagrees with an expert? Find another expert, of course!

I decided to ask one of my classes, all non-Finnish MSc students and engineers, and one a student of maths. The outcome; the majority favoured H-M's method, and the Africans used my method. Oh, and one student got the answer wrong.

Remember that numbers are fun and, as the Dr Seuss book points out, fun is good!