What is the power of 10 when 0.28 is written in scientific notation

The power of 10 is -5 

Move the decimal point to the right until the first significant number and in this problem it is 2. It took 5 places to the right until going past the 2 and the number would be negative because going right past the decimal point will make any power negative. 

Not sure what the question is but i hope this x = years100 * x

Ithink it may be 10^3,that mean 10 'exponent ^3 would the population scientific in terms to evaluate by such and