Ok, so first convert both the numbers to improper fractions. (Multiply the denominator of the fraction by the whole number and add the numerator of the fraction)
Then keep the first number the same, change the division symbol to a multiplication symbol and use the reciprocal of the second number. (flip the numbers so that the denominator becomes the numerator and the numerator becomes the denominator.)
For example, if it's 4 1/3 divided by 1 1/3, multiply the denominator, 3, by the whole number. For 4 1/3, it would be 3*4 to get 12. Then add the numerator to get 13. 4 1/3 is then represented as 13/3. Do the same for 1 1/3 to get 4/3. Do the reciprocal to get 3/4. Then instead of dividing, do 13/3 times 3/4. Since the denominator of 13/3 and the numerator of 3/4 are the same, cross them out. You're left with 13/1 times 1/4. Multiply to get 13/4, or 3 1/4.
Tip: Use a website called Wolfram Alpha. Type in mixed numbers by using 4 (space) 1/3 (type times, don't put *) whatever number. wolframalpha.com
