Sometimes you'll be asked to convert mixed numbers into improper fractions, and vice versa. Once you get the hang of it, you'll be doing it in your sleep.
Let's start by looking at mixed numbers and improper fractions visually.
This is 

If we divide each whole circle into fourths, we can count the number of blue fourths. Shazam! There are 11 blue fourths, or 
This is 

As you can see we have 3 wholes and 1 section remaining, or 3 1/3.
You could also think of mixed numbers as sums of whole numbers and their parts. For example 3 1/3 is really 3 + 1/3





And try another example...
is 
This time the common denominator is 4.





Example 1

Example 2

| Example 1 | |
| 5 goes into 19 three times with four remaining. |
| 3 is the whole number. 4 is the numerator. 5 is the denominator, which stays the same. |
| Example 2 | |
| 2 goes into 11 five times with one remaining. The denominator stays the same. |
| 5 is the whole number. 1 is the numerator. The denominator stays the same. |