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.
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.