Well....
For up elevations you add yardage, for down the opposite. For headwinds you add yards, for tail winds you subtract yards. For crosswinds you divide the wind into vertical and horizontal components and adjust accordingly.
Now, I'm an old effer. Back in my day, one would have learned to figure this out by the sixth grade. I realize it's different now, for some reason. Mathematics is for figuring out how low to drop your jeans, how much underwear to show, and whether the underwear should exhibit substantial brown spots.
There's also the question of how much you should pay for a dime bag. Modern life is really tough.