When you battle, capture, scan, or are given a pokemon, you will notice that its Pokedex description has been added to the Dex Gallery Section, thereby giving the gallery some use. The Pokedex will contain the pokemon's stat rating which controls how much damage it does. In the previous example, I'd failed to mention that Amby and Charmander have the same base Defensive stat ratings, barring HP which Charmander has more of. That said, Their Defense and Special Defense is generally the same until Charmander and Amby evolve. Amby's evolutionary line stays Fragile while Charmanders becomes a bit bulkier. Anyway, the stat ratings are displayed using +, -, and ~. The + indicates that the pokemon is exceptionally good with this stat. - indicates the opposite and ~ indicates that it's of neutrally good use in that stat. So the stat entries in the dex will look like this.
Pokemon #
Nutrinurse: The Nurse Pokemon
Ability...
Entry...
Stat Rating
HP+
Attack~
Defense~
Sp. Atk+
Sp. Def+
Speed+
Here's where the math comes in. If there's a + next a particular stat, all attacks benefited by that stat get +3 damage for each level the attacker grows. If there's a ~ then +2. If there's a - then +1
Evolution is a helper big time in stats if you're struggling. If a pokemon has three stages of evolution and it's reached a point where it can evolve to second stage, attacks of stats with + next to them in the next stage get a helpful +15. Attacks of stats with a ~ in that next stage get +10 and those with - get plus 5. With Last stage it changes. + gets +30, ~ gets +20, and - gets +10. Example.
Stagly Lvl 7
HP-
Attack+
Defense~
Sp. Atk-
Sp. Def~
Speed~
Attacks
Moves
Tackle - 30
Harden - /
Bug Bite - 32
Stagly Evolves
Arbeetle Lvl 7
HP~
Attack+
Defense+
Sp. Atk-
Sp. Def~
Speed-
Attacks
Moves
Tackle - 45
Harden - /
Bug Bite - 47
Arbeetle Evolves
Beetelord Lvl 10
HP~
Attack+
Defense+
Sp. Atk-
Sp. Def-
Speed-
Attacks
Moves
Tackle - 75
Harden - /
Bug Bite - 77
Pokemon of Two stage evolutions and Pokemon without evolutions are just treated so the first stage is treated as the middle and the last stage is treated as such where pokemon that haven't an evolutionary line will be treated generally as final stages until another region comes and they potentially get evolved forms or pre-evolved forms.
Again. I do all the math for you with the help of a calculator so I don't strain my weakened mind. In other words, all you have to do is RP. Have fun n_n'