When it comes to calculations, the most useful ability is not to be able

to

caculate it exactly, caculator or no, but to quickly be able to estimate a

ball

park answer or approximation.

Who needs to know that  22uH at 137kHz has 18.93 ohms reactance.

Its quicker to think  " a bit more than 20 times a bit less than 0.14,

times

 6-and-a-bit
...    is  2.8 times 6-and-a-bit ,  so call it 18 ohms"

Andy  G4JNT

I agree with Andy. Part of my degree course with the Open University was a
unit called Modelling with Mathematics. At the time (mid 1970s) we were
provided with circular slide rules, which were adequate for determining
whether something would work or not. At the time electronic calculators had
become available and many students complained about having to use the slide
rule. The course team responded by saying that the slide rule gave a better
understanding of the mathematics involved.

Peter, G3LDO