> By the mid-1960s, more than a million slide rules were sold in the US each year. The device became for the mathematically minded what the stethoscope was for

> By the mid-1960s, more than a million slide rules were sold in the US each year. The device became for the mathematically minded what the stethoscope was for the physician: a badge of professionalism as well as a practical tool. My understanding is that the act of internalizing the meaning of the exponents is a tremendous enabler of understanding; engineers of old achieved a better feel for the task than us moderns with all of the fancy software. Restated: there may be some good pedagogy in having the initial course or two do things in a classical way ahead of moving on to all of the new methods.