What's 1+1? There are some answers to this question in our Dr. Math archives: 1 + 1 Does 1 + 1 make 2 or 11? What is 1 plus 1? What is 1 plus 1? One Plus One Are you sure that 1 plus 1 equals 2? Proof that 1 + 1 = 1? Can you shed any light on this subject? Proof that 1 + 1 = 2 Can you prove that 1 + 1 = 2?