Andrew Jackson did not sign it. Any simple Google searching would tell you this. He was 9 years old when it was signed. He himself, did not sign it.

The article you listed also doesn't say he signed it. It states the ages of various early American figures at the time the Declaration was signed. You clearly didn't read/comprehend your own source.

I don't believe the article you linked to is saying that he signed it, just that at the time of its signing he was 9.

I just looked up the names of all 56 people who signed the Declaration of Independence and did not see his name.

Andrew Jackson didn't sign the Declaration of Independence. That is a list of participants in the American Revolution - those who signed the Declaration are denoted with a " ^ " mark. According to this list, the youngest signatories were Thomas Lynch, Jr., and Edward Rutledge, who were 26.