Why do even the simplest calculators feature a square root key?

[Dieter]

While this forum is clearly focused on midrange and high end calculators, there are also the ubiquitous simple four function devices that offer nothing but the four basic arithmetic operations. Even HP offers these, e.g. the EasyCalc 100, so I take the liberty of posting this in the General Forum. ;-)

While it is clear that the typical user of such a device does not care about logarithms, powers or trigonometric functions, and adding a few numbers or calculating a markup essentially is all that it is used for, I always wondered why most of these simple devices still have a √ key. I have never seen anyone calculating a square root on such a calculator, so I wonder why this function exists at all. Where and why does the typical user of a calculator that does not feature anything beyond +, –, × and ÷ need a √ key? Or is it simply because this function is so easy to implement that it is included only because of that?

Dieter