http://www.fogu.com/hm9/farm/trees.php
http://www.fogu.com/hm9/farm/fields.php
9 * 6 = 54, not 45.**
**According to current number theory
Edit: Also, on this page:
http://www.fogu.com/hm9/village/windmills.php
I don't understand how 10 * any of those values comes out to 4 and a half hours (270 minutes). With just a strong wind, it's 5 hours (300 minutes). With a strong wind and blowing on it, it's 3 hours, 20 minutes (the example with the 10 put in individually says 20 minutes each, which is the strong wind + blowing on the microphone).