The classic way to convey the error that exists in a measurement is a formula that shows the obtained measurement (X) as a sum of a true score plus some error. One version of this formula is: X = T + e. With this formula in mind, obtaining more precise measures depends on reducing error.
  Mega is the prefix meaning one million, therefore there are one million (1,000,000) gallons in a mega gallon.
There are 231 cubic inches in 1 gallon. To calculate the volume of a container in gallons when you have the volume in cubic inches, divide the number of cubic inches by 231. 1  Example: The volume of a tank is 3042 cubic inches.2  Find the volume in gallons.alculate gallons from cubic meters. There are 264.17 gallons for every 1 cubic meter. If you have the volume of a container in cubic meters, you can calculate the volume of that container by multiplying the volume in cubic meters by 264.17. 1  Example: The volume of a pool is 8.12 cubic meters.