How does "by one stat, by two stats and by three stats" work?

Question

If I use Defense Curl, it is said my defense is powered up by one stat.
If my defense normally 100 is, what happens then?
And what happens if I use Iron Defense and Cotton Guard?

Answer 1

So in-battle stat-boosting works like this:

1 boost = The stat is multiplied by 1.5, so if your stat was 100 it will now be 150.

2 boosts = The stat is doubled, so if your stat was 100 it will now be 200

3 boosts = The stat is multplied by 2.5, so if your stat was 100 it will now be 250

4 boosts = The stat is tripled, so if your stat was 100 it will now be 300

5 boosts = The stat is multiplied by 3.5, so if your stat was 100 it will now be 350

6 boosts = The stat is quadrupled, so if your stat was 100 it will now be 400.

The same applies to lowered stats, just in reverse. Note that all stats are reset after battles.

So if you were to use Iron Defense and then Cotton Gaurd, your would get 5 boosts in defense, so your defense stat would go from 100 to 350.

Answer 2

Here it is http://Pokemondb.net/pokebase/94255/what-improves-your-attack-more-swords-dance-claws-hustle-boost .i think it works the same with defence and sp defence