View more at http://www.MathTutorDVD.com. In this lesson, you will learn how to add two mix numbers and fractions that have like denominators. In order to perform the addition, first we add the whole numbers that are in the mixed number. Next, we add the fractions in the usual way, which involve keeping the same common denominator and adding the numerators. After the addition is done, then we simplify the result in the usual way. The answer is always presented in lowest terms, or simplest form.