*Note: this is actually an example of what you would call scientific notation.
To solve this, let's apply this method to a simpler method. When you multiply 13 by 10, you get 130 right? And when you multiply 13 by 10 to the power of 2, you get 1300 right? The exponent is the amount of zeroes you add after the factor. If the exponent is negative, you simply subtract the amount of zeroes. If there are no zeroes at the end, then you move the decimal however many times to the left.
Therefore, 1.08 x 10 to the power of negative 3 would be 0.00108. The decimal was moved 3 places to the left. Hope this helps!