As you can see, the exponent of 10 is the number of places the decimal point must be shifted to give the number in long form. A positive exponent shows that the decimal point is shifted that number of places to the right. A negative exponent shows that the decimal point is shifted that number of places to the left.
In scientific notation, the digit term indicates the number of significant figures in the number. The exponential term only places the decimal point. As an example,
46600000 = 4.66 x 107 This number only has 3 significant figures. The zeros are not significant; they are only holding a place. As another example,0.00053 = 5.3 x 10-4 This number has 2 significant figures. The zeros are only place holders.