Answer
Exact answer = $3\frac{3}{8}$
Work Step by Step
$14\frac{3}{4}$ - $11\frac{3}{8}$
Estimation:
$14\frac{3}{4} \approx 15$
$11\frac{3}{8} \approx 11$
Therefore
$14\frac{3}{4}$ - $11\frac{3}{8}$ $\approx$ 15 - 11 = 4
Exact Calculation:
$14\frac{3}{4}$ - $11\frac{3}{8}$
= $14\frac{3\times2}{4\times2}$ - $11\frac{3}{8}$
(8 is the least common denominator)
= $14\frac{6}{8}$ - $11\frac{3}{8}$
= $14$ + $\frac{6}{8}$ - ($11$ + $\frac{3}{8})$
= $14$ + $\frac{6}{8}$ - $11$ - $\frac{3}{8}$
= ($14$ - $11$) + ($\frac{6}{8}$ - $\frac{3}{8}$)
(Solving whole parts separately and fractional parts separately)
= $3$ + $\frac{6 - 3}{8}$
= $3$ + $\frac{3}{8}$
= $3\frac{3}{8}$
The estimate was 4, so the exact answer of $3\frac{3}{8}$
is reasonable.