To add $\frac{2}{5}$ and $\frac{1}{2}$, we first need to find a common denominator.

The least common denominator (LCD) of 5 and 2 is 10.

Now, rewrite both fractions with a denominator of 10:

$\frac{2}{5} = \frac{4}{10} \quad \text{(Multiply both the numerator and denominator by 2)}$

$\frac{1}{2} = \frac{5}{10} \quad \text{(Multiply both the numerator and denominator by 5)}$

Now, add the two fractions:

$\frac{4}{10} + \frac{5}{10} = \frac{9}{10}$

So, $\frac{2}{5} + \frac{1}{2} = \frac{9}{10}$.

Would you like more details on this process? Or do you have any other questions?

Here are some follow-up questions:

1. How do you find the least common denominator for other fractions?
2. Can you subtract fractions using the same method?
3. What if one fraction is larger than the other, how do you deal with that?
4. How do you multiply fractions?
5. Can you simplify fractions, and if so, how?

Tip: Always find the least common denominator before adding or subtracting fractions to ensure accuracy!