With a little bit of effort you can work out the exact answer
and do not need to estimate.
90/9 is 10.
But you want 87/9. The numerator is 3 less so the quotient will
be 3/9 less. Now, 3/9 = 1/3. So the exact answer is 10 minus 1/3
which is 92/3. Not that hard, was it?