glance down at the RNAV box, NAV 3, then see the wind, drift angle etc, no need for complex/simple arithmetic.
As for sine tables etc, come on. Just guestimate it, it changes all the way down the approach anyway if thats where you're using it.
Is the wind just off the nose by about 20 degrees? ok, so use about 1/3 of wind speed. 45 degrees? use about 2/3 wind speed. then up to 90 degrees? use all of it.