Fractions represent parts of a whole and do not always have to be less than 1 (a whole). While proper fractions represent quantities smaller than 1, improper fractions represent quantities that are 1 or larger. If we multiply or divide both the numerator and denominator of a fraction by the same number (factor), the resulting fraction is equivalent to the original fraction. This property is used to both simplify (reduce) fractions and to expand fractions.
You have seen that multiplying and dividing mixed numbers is very similar to multiplying and dividing fractions. The only difference is that the mixed numbers must first be converted into improper fractions before the properties for multiplying and dividing fractions can be applied.