so small as

English as a Second Language English Vocabulary, Grammar and Idioms
1
  1. The difference was so small as to not be worth arguing about.
  2. The difference was so small as not to be worth arguing about.
  3. The difference was so small as to be worthless arguing about.
    Please correct the above.
2

Could anyone help me?

3

Beeesneees,
Will you not help me?

4

I would put it like: “The difference was so small that it was not worth arguing about.”

5

I agree that Eugene’s phrase is the only natural sounding one.