Question

Use rounding or compatible numbers to estimate each product or quotient.

Answer 1

Part 1

Using rounding or compatible numbers, we estimate the product

$5\times2 \frac{3}{5}$
to
$5\times3$

Therefore, the estimate of the product $5\times2 \frac{3}{5}$, using rounding and compatible numbers is about 15.



Part 2

Using rounding or compatible numbers, we estimate the quotient

$25\frac{7}{8}\div2 \frac{8}{9}$
to
$27\div3$

Therefore, the estimate of the quotient $25\frac{7}{8}\div2 \frac{8}{9}$, using rounding and compatible numbers is about 9.



Part 3

Given that Mr. Garcia's class ate $3\frac{2}{3}$ pizzas, Mrs Rizzoli's class ate $4\frac{1}{8}$ pizzas, and Mrs. Tindal's class ate $3\frac{1}{4}$ pizzas.

Using benchmarks, we estimate the total number of pizzas eaten by all three classes as follows: $3\frac{3}{4}$, $4$ and $3\frac{1}{4}$

Thus, the total number of pizzas eaten by all three classes is given by

$3\frac{3}{4}+4+3\frac{1}{4}=11$

Therefore, the total number of pizzas eaten by all three classes is about 11.