Why is 1+ 1 equal to 2?

In the first case, if you say that 1+ 1 is a simple elementary school arithmetic formula, you can also rate the following situations.

① If the units of two "1" are the same, the result is 2. For example, 1 mijia 1 meter equals 2 meters, and one duck plus one duck equals two ducks.

② If the two units of "1" represent different units of the same quantity, 1+ 1 may not be equal to 2. For example, 1 m plus 1 cm equals 1.0 1 m, and also equals 1065438.

③ If the two units of "1" represent different quantities, the two "1" cannot be added. If 1 kg is added on the basis of 1 m, it has no practical significance.

In the second case, when you say 1+ 1 is representative, do you mean Goldbach's conjecture? This conjecture has not been finally proved.

The third situation: what if it is a brain teaser? There are many answers. For example, if you are a crossword puzzle, you can have the solution of "Wang", and so on.

The fourth case: if it has other meaning, then if you say 1+ 1 equals several, then it equals several. For example, my 1+ 1 is = 1 1.