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 0.0037854117840007 cubic meter in a gallon. 1 Gallon is equal to 0.0037854117840007 Cubic Meter. 1 gal = 0.0037854117840007 mÂ³. A gallon is a unit of volume measurement used widely in the US and a few other countries of the world.