I know how to do arithmetic, but I still use my PC or a calculator because I am not entirely sure that I am accurate. I use "units" as well extensively, it can be used for much more than just unit conversion. You can do complex calculations with it.

You can solve stuff like:

> If you walk 1 mile in 7 minutes, how fast are you walking in kilometers per hour?

  $ units -t "1 mile / 7 minutes" "kilometers per hour"
  13.7943771428571

You need some basic knowledge to even come up with "1 mile / 7 minutes" and "kilometers per hour".

There are examples where you need much more advanced knowledge, too, meaning it is not enough to just have a calculator, for example in thermodynamics, when dealing with gas laws, you cannot simply convert pressure, volume, and temperature from one unit to another without taking into account the specific context of the law you’re applying (e.g., the ideal gas law or real gas behavior)", or for example you want to convert 1 kilowatt-hour (kWh) to watts (W). This is a case of energy (in kilowatt-hours) over time (in hours), and we need to convert it to power (in watts), which is energy per unit time.

You cannot do:

  $ units -t "1 kWh" "W"
  conformability error
  3600000 kg m^2 / s^2
  1 kg m^2 / s^3

You have to have some knowledge, so you could do:

  $ units -t "1 kWh" "J"
  1 kWh = 3600000 J
  $ units -t "3600000 joules / 3600 seconds" "W"
  3600000 joules / 3600 seconds = 1000 W

To sum it up: in many cases, without the right knowledge, even the most accurate tool will only get you part of the way there.

It applies to LLMs and programming, too, thus, I am not worried. We will still have copy-paste "programmers", and actually knowledgeable ones, as we have always had. The difference is that you can use LLMs to learn, quite a lot, but you cannot use a calculator alone to learn how to convert 1 kWh to W.