There is absolutely NO POINT is giving more than 3 decimal figures, because we ignore them unless it is a serious scientific calculation.
So, I am going to calculate how many ounces in 13.215 gallons.
The answer 374.513 ounces.
20 gallons = 2,560 ounces.
13.2 gallons is 1,689.6 ounces.
8320 ounces is 65 gallons.
169 ounces is 1.32 US gallons.
63 US gallons is 8,064 ounces.
5.22 fluid ounces is 0.04 gallons.
Eleven US gallons is 1,408 ounces.
24 US gallons is 3,072 ounces.
211 fluid ounces is 1.648 gallons.
15,360 fluid ounces is 120 gallons.
15 US gallons = 1,920 ounces.
400 US gallons = 51,200 ounces.