Quincy says that 3 is a good estimate for 3.4 x 0.09, is he correct? why?

Quincy says that 3 is a good estimate for 3.4 X 0.09, is she correct? Why?
When we say estimates meaning it is not the exact answer but close to what is the exact.
Now, if Quincy estimated 3 as the product of 3.4 * .09, then let’s check if she has the correct estimates.
=> 3.4 estimates is 3
=> 0.09 estimates is 0.1
Now the answer is 0.3 and not 3.
Thus, Quincy’s estimate is wrong.