You turn the mixed fractions into improper fractions and then you multiply how you would multiply normal fractions and once you get your result you turn it into a mixed fraction again. For instance:
1 1/3 X 1 1/3
The whole number one is 3 as a numerator so add it to 1
4/3 x 4/3 which is qual to 16/9. 16 divide 9 is equal to 1 7/9
Answer: 1 7/9