Question

Can someone please explain to me the order of magnitude calculations?

Answer 1

Order of magnitude calculations use the nearest power of 10. For example
if you want to find 0.2 * 8 you would say 1/10 (0.2 is closest to 10^-1) times 10
or 1 which is within a factor of 10 of
the actual answer is 1.6

Answer 2

@klimenkov basically I need to use the order of magnitude calculations to calculate the number of gallons of gasoline used by Americans each year

Answer 3

@klimenkov ???