Concatenate without losing leading zeroes?

[paquirl]

Column A has numbers that should all be 6 digits. Some have leading zero(es).
Column B has numbers that should all be 5 digits. Some have leading zero(es).
Column C should combine both A and B with every cell having an 11 digit number.

 

[Joe4]

it wont let me select both formulas as the solution to this thread

No, you can only choose one.
You can like the other one, but that is about it.

 

[Fluff]

Only one post can be marked as the solution, so I would suggest you flag Joe's post, as he gave you the correct answer.