See how to add $\frac{2}{3}$ to $\frac{1}{6}$.

We have to make both denominators equal. One way to make it, is to multiply the denominator of the first fraction by 2. In order to make the new fraction equivalent, we also multiply the numerator by 2.

$\frac{2}{3} + \frac{1}{6} = \frac{2.2}{3.2} + \frac{1}{6}$

Now, as the two fractions have the same denominators, we we can sum them up

$= \frac{4}{6} + \frac{1}{6}$

$=\frac{4 + 1}{6} = \frac{5}{6}$ (answer)