I dunno. A third of 32 is almost 11, so two thirds is almost 22; I need a calculator to find 3/4 of 32. (Half is 16; half again is 8; 32 less eight is 24. While holding course, managing descent and talking to Tower on the radio in IMC. Too much for me.)
I'm firmly in the camp of "close enough," and find written test questions whose answers must be calculated to two decimal points to be silly wastes of time. What's the real difference between 22 knots crosswind component and 24 knots? Both are higher than the "demonstrated crosswind" in my Owners Manual, and the actual real value is 22.63 knots by my calculator for a 45° wind.
Besides, aren't we approximating wind angle anyway? Wind angle may be reported accurately on ASOS, but runway headings are in 10° increments.
So i lump the wind into big categories and get close enough.
Less than 20° = zero
20-40° = half
40-60° = two thirds
>60° = reported windspeed
Quick, easy, simple. No calculator needed, no decimal points to used, easily done in my head. And it eliminates the 5° variability in runway heading, too.
Half, two thirds, all works for me, and is easy to remember.
And for lighter winds like 17 knots, unless it's close to direct cross, I don't bother figuring the components. If it IS close to direct cross, I just think the whole reported winds are crosswind.