I asked the doctor to explain diabetes and especially the kidney failure side of things. He said that only two per cent of David kidneys were operating. I had to stop him again and explain what two percent meant because percentage is a concept Yolngu just do not understand. So I drew a kidney shape on a piece of paper and shaded in about two percent. 'That's how much is still working', I told David. 'The rest is, like, "dead".' (99) ...Reference: Trudgen, Richard. Why Warriors Lie Down and Die (2000)
As mentioned previously, percentage is a concept that Yolngu have great trouble with. As a cultural group they just do not understand it. Even people with seemingly good Western education standards have problems with it.
To use percentage as a quantitative measurement and expect to convey an accurate concept to Yolngu is very dangerous as far as their health is concerned. It was equivalent to saying to David, 'You have only two wup-wups of kidney working.' It gave him no picture at all but simply added to his confusion. David would not even have realised that percentage is a measurement of quantity. The concept is just not understood, so it is very difficult for a patient to frame and ask questions about it.(109)
Trudgen's broader view is that communication between Yolngu and Balanda (whites) breaks down in three related areas (1) Language (2) World view (3) Culture. In this particular case study he documents 8 world view problems and 2 language problems which all contributed to David declining to change his diet (smoking, eating salt and sugar). So, this information about Yolngu not understanding percentage has to be situated in a far broader context. By drawing a diagram of the kidney and shading in 2 parts out of 100 of that diagram, you could say that Trudgen did explain percentage to David, without using the word percentage. Nevertheless, we are still a long way from the concept being internalised and understood fluently.