To round it, you look at the fraction. If the top is greater than or equal to one-half of the bottom number, you round up and add one to the whole number. If it is less than one-half the bottom number, you round down and your answer is simply the whole number by itself.
In this case, half of the bottom number, 8, would be 4. However, the top number, 5, is larger than 4. Therefore, you round up and add one to the whole number (4).
The answer would then be 5.