Basically half of the chemistry is about remembering and Half is about understanding and calculating.

In case of inorganic chemistry most of the fix need to be remembered and their also involved lot of concepts but without remembering you cannot apply the concepts in case of inorganic chemistry unit to remember most of the reaction in case of organic chemistry you can understand them reaction mechanism and after that you can find the product of an addition to in case of physical chemistry unit to be good at mathematics not very dance but little bit and practice.