To add $\frac{8}{10}$ and $\frac{4}{100}$, we first need to express both fractions with the same denominator. Since the denominator you're asking for is 100, we need to convert $\frac{8}{10}$ into a fraction with 100 as the denominator.

Step 1: Convert $\frac{8}{10}$ to a fraction with 100 as the denominator:

$\frac{8}{10} = \frac{8 \times 10}{10 \times 10} = \frac{80}{100}$

Step 2: Add the fractions:

Now, we can add $\frac{80}{100}$ and $\frac{4}{100}$: $\frac{80}{100} + \frac{4}{100} = \frac{80 + 4}{100} = \frac{84}{100}$

So, $\frac{8}{10} + \frac{4}{100} = \frac{84}{100}$.

Final Answer:

The sum is $\frac{84}{100}$.

If you need any further clarification, feel free to ask!

---

Here are some related questions to explore:

1. How do you convert a fraction to have a common denominator?
2. What is the simplest form of $\frac{84}{100}$?
3. How do you add fractions with different denominators?
4. What happens when the numerators and denominators are both divisible by the same number?
5. Can you subtract fractions with the same denominator?

Tip: Always convert fractions to a common denominator before adding or subtracting them!