Answer
$21\frac{1}{8}-20\frac{1}{4}=21.125-20.25=0.875=\frac{7}{8}$ inches
Work Step by Step
To change the fractions to decimals, first we need to write $\frac{1}{8}$ and $\frac{1}{4}$ as decimals. We do this by dividing:
$~~~~0.125$
$8\overline{)1.000}$
$~~~~~~~\underline{8}$
$~~~~~~~20$
$~~~~~~~\underline{16}$
$~~~~~~~~~~40$
$~~~~~~~~~~\underline{40}$
$~~~~~~~~~~~~~0$
$~~~~0.25$
$4\overline{)1.00}$
$~~~~~~~\underline{8}$
$~~~~~~~~20$
$~~~~~~~~\underline{20}$
$~~~~~~~~~~~0$
Therefore, $21\frac{1}{8}=21.125$ and $20\frac{1}{4}=20.25$. We find the difference:
$21.125-20.25=0.875$ inches
We convert this to a fraction:
$0.875=\frac{875}{1000}=\frac{7}{8}$
This matches our answer to Exercise 34. We see that the fraction and decimal methods yielded equivalent answers, although it was simpler to work in fractions.
