i have reached level 1oo in smithing but it wont let me choose the perk to make dragonscale armour

Have you leveled up and have a perk point available or is it just not letting you select the skill? Has your skill been boosted by an item you are wearing, if so that doesn't count.

at one tim e i was wearing some smithing gloves but they have been removed, i have the perk point, i am level 100 but it wont let me set dragonarmour

Basically this.

Edit: Op, that sounds strange, do you have either the daedric smithing or glass smithing perks? You need one of those to get that perk by the way.

If you don't have the light armor perks up to glass or heavy up to daedric then you can't select the perk.

As said above, do you have the perk for both Glass and Daedric? You need both. You do have a perk point to spend, right?

To get Dragonbone and Dragonscale, a character needs every prior Perk on the "Light Armor" Side from Steel to Elven to Adavnced to Glass, or the entire Heavy side from Steel to Daedric filled before being able to select Dragon.

No you don't need both, but you do have to have one or the other.

It is actually easier to go up the light armor side of the smithing tree because from steel smithing to glass to dragon smithing takes just as many perks to get from steel smithing to daedric smithing.