When you want to add fractions with different denominators-which are the bottom numbers- you have to find the lowest numbers that you can multiply to go into both numbers. I know that you can multiply 8×3 to get 24. And that I can multiply 12×2 to get 24. So 24 would be what we change the denominators to.
But we can't just change the denominators. I have to change the numerators, too. Since I multiplied 8×3, I have to multiply the numerator by 3, also. 3×3=9. The new fraction is
.
Do the same thing to the other fraction. But we will multiply by 2. 1×2=2. So now we have
. We can now add.
+ Only add the top numbers. We have 
That fraction cannot be reduced, so is the final answer.
But we can't just change the denominators. I have to change the numerators, too. Since I multiplied 8×3, I have to multiply the numerator by 3, also. 3×3=9. The new fraction is
Do the same thing to the other fraction. But we will multiply by 2. 1×2=2. So now we have