Ability increases on monsters handled how?

[Ravingdork]

How is one supposed to, RAW, handle ability score increases (every four levels) for monsters with racial hit dice and class levels?

[Kyras Ausks]

normaly...?...

[Aioran]

Give them an ability score increase with every 4 HD, like everyone else.

[Rathendar]

What Aioran said, but also keep in mind that if the monster has four or more racial HD those points are already included as spent in its statblock. So if you have a 7HD monster and add a class level of barbarian, that would bring it to 8HD total and give another stat point to spend. Also adding a level in a PC(not NPC) class gives it a stat boost as well. (+4, +4, +2, +2, 0, -2 i think)

[Cheapy]

Every four HD you add, they get a +1. if you have a 3 HD creature, and you advance it to 8, you get a +1, since that's only 5 added HD.

[eakratz]

That doesn't seem right. If you go from 3 to 8 HD, why wouldn't it be two +1s?

Edit: Could this be the line you are referring to?

PRD under adding class levels wrote:

This functions just like adding class levels to a character without racial Hit Dice.

The assumption being, pretend the monsters racial HD are 0 for the purpose of classes.

[Ravingdork]

Kyras Ausks wrote:

Normally...?

As others have shown after you, it is not so easy. How is it "normally" done?