Aviation requires mental arithmetic skills. There will be those on the new fangled magenta line a/c, even worse the FBW brigade who will disagree. Any answers are always in the i-pad, FMC or Japanese brain in their flight bag. However, they have forgotten the most basic rule that the best computer on the a/c is between your ears; or it should be. A big shiny jet does not negate basic physics & arithmetic. In jets there are moments where legal limits come into force and need an instant decision. X-winds & tail winds are one of them, fuel flow & endurance in non-normal config another. And god forbid those guys who do load sheets on a calculator and still get it wrong.
In PPL light a/c flying there are many more scenarios, perhaps. 1 in 60 rule can be applied in many useful ways. Drift angles in holding patterns; wind vectors on finals another. I came from an era where mental maths was the norm and we kept it alive and well all through university. At flight school I'd become rusty and it was a hindrance. The excellent local pub had a dart board and that was the most enjoyable saving grace for removing the stress of VFR navigation calculations.
For wind vectors I always use 00 30 45 60 90. Headwinds are 100% .9.7.5.0. The x-wind is reversed starting with 100% at 90 degrees. It's easy. Throw away the calculator and engage the dormant grey cells.