In adding similar and dissimilar fractions, first add the whole numbers if there is/are any. In similar fractions, the numerators are the only ones being added. If the sum of the numerators is greater than the denominator, then you have to regroup by changing the improper fraction to a mixed fraction. The answers should be expressed in the simplest form as much as possible. In adding dissimilar fractions with regrouping, first, you need to convert the dissimilar fractions into similar fractions by getting the LCD (Least Common Denominator). After that, add the whole numbers and fractional parts. Simplify the answer whenever possible.