This is how you add
Since our denominators match, we can add the numerators.
4 + 8 = 12
The sum we get is
The last step is to reduce the fraction if we can.
To find out, we try dividing it by 2...
Nope! So now we try the next greatest prime number, 3...
Are both the numerator and the denominator evenly divisible by 3? Yes! So we reduce it:
Let's try dividing by that again...
Nope! So now we try the next greatest prime number, 5...
No good. 5 is larger than 4. So we're done reducing.
There you have it! Here's the final answer to 4/9 + 8/9