Answer
Exact answer = $2\frac{5}{8}$
Work Step by Step
$14\frac{7}{8}$ - $12\frac{1}{4}$
Estimation:
$14\frac{7}{8} \approx 15$
$12\frac{1}{4} \approx 12$
Therefore
$14\frac{7}{8}$ - $12\frac{1}{4}$ $\approx$ 15 - 12 = 3
Exact Calculation:
$14\frac{7}{8}$ - $12\frac{1}{4}$
= $14\frac{7}{8}$ - $12\frac{1\times2}{4\times2}$
(8 is the least common denominator)
= $14\frac{7}{8}$ - $12\frac{2}{8}$
= $14$ + $\frac{7}{8}$ - ($12$ + $\frac{2}{8})$
= $14$ + $\frac{7}{8}$ - $12$ - $\frac{2}{8}$
= ($14$ - $12$) + ($\frac{7}{8}$ - $\frac{2}{8}$)
(Solving whole parts separately and fractional parts separately)
= $2$ + $\frac{7 - 2}{8}$
= $2$ + $\frac{5}{8}$
= $2\frac{5}{8}$
The estimate was 3, so the exact answer of $2\frac{5}{8}$
is reasonable.
