1. Similar fractions are those which have the same denominator. To change dissimilar fraction to similar fractions, you express them as a equivalent with a common denominator. For example 2/12, 3/12
2. To add similar fraction one should ensure that both the numerator are same and then add the numerator and put that on the denominator. If there is need to simply the fraction then you should first simplify the fraction.
For example:- 1/4+4/4= 5/4
Here as we see that bot number denominator are same so it's addition is done easily