10/12+1/2 is 1 1/3.
Common denominator is 12, so multiply the 2 by 6. Do the same to the 1, which turns into 6. Now you can directly add the fractions. 6+10 is 16, the fraction becomes 16/12. This simplifies to 1 1/3!
* you turn it into a whole number because you are simplifying an improper fraction.
This is when the numerator is greater than the denominator.