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.
Since 1 kilogram is equal to 2.20462 pounds and 1 US gallon is equal to 3.79 litres, the density of gasoline can be calculated to be 6.183 pounds per gallon, for example, a gallon of gasoline weighs 6.183 pounds.