A standard form should be in the form a.bcdef ×109 Thus the decimal must be after the first non-zero number. The power is the number of times you have to move the decimal point so that it's positioned after the first nonzero number If you move to the left, the power is positive and if you move to the right, the power is negative From 1930.54 you can see that the decimal must be after 1 . We have to move the current decimal point three (3) times to the left in order to position it after the 1, hence the power is positive 3 1930.54=1.93054×103