"one years old"

I just heard someone say:

"my baby just turned one years old"

Which sounds super weird to me - so I googled a little and found similar sentences:

How Old Are Dogs When They Turn 1 Years Old in Human Years It has been said that a dog who is 1 years old is 7 years old in human years.

Can you really say "years" after "one"?

Solution 1:

It is a quaint way of speaking which some people fall into, thinking for some reason it is correct - I think!

I have heard people say 'one pounds, fifteen pence', or the most ridiculous example was listed on an invoice from a funeral director, which I saw. It said '1 no. stained oak veneered coffins'.