#### Answer

Estimate: $10$
Exact: $10\frac{1}{8}$

#### Work Step by Step

Estimate: Round the numbers to 5 and 2 and multiply.
Exact: Turn numbers into improper fractions: $\frac{9}{2}, \frac{9}{4}$
multiply: $\frac{9}{2}\times\frac{9}{4} = \frac{81}{8}$
Convert to a mixed number: $10\frac{1}{8}$