What is left when $\frac{1}{8}$ is subtracted from $\frac{3}{4}$?
I want to subtract two fractions with different denominators, so I need to find a common denominator first. The least common multiple of 8 and 4 is 8, so I can rewrite $\frac{3}{4}$ as $\frac{6}{8}$ by multiplying the numerator and denominator by 2. Now I have $\frac{6}{8} - \frac{1}{8}$, which is easier to subtract because they have the same denominator. I just need to subtract the numerators and keep the denominator: $\frac{6}{8} - \frac{1}{8} = \frac{5}{8}$. 