> When Illustrating a mathematical idea, the first thing you need to decide is the scale.<p>I have spent much of my life illustrating mathematical ideas, and scale is <i>never</i> the first thing I decide. Most commonly it stays abstract and there is no scale; it's flexible and I can zoom in and out at will. Sometimes I will choose a scale partway through or towards the end of an explanation, if I want to use a specific analogy, but I can comfortably rescale it to something else - the scale is never fixed.<p>Interesting to see such a different view.