Answer:
81.
Explanation:
in order to find 8.1×10, you'd want to move your decimal place one to the right (hence the ONE zero on the end of 10). so, if you wanted to do 8.1×10, it would be 81.
if you wanted to do 8.1×100, it would be 810 because you'd move the decimal place two to the right (because there are two zeroes on the end of 100)
if you wanted to do 8.1×1,000, your answer would be 8,100. moving the decimal place three to the right (hence the three zeroes on the end of 1,000) you'd get 8,100.
Hope this helps! <3