How do we know 2 + 2 = 4?

Question

How do we know 2 + 2 = 4?

Answer 1

Because when we stacked two sets of blocks on top of each other as a toddler there was a total of four blocks. We know this because each block as we were told in first/second grade were equivalent to the numeral one. We have assigned this as a truism. This does not mean that the divine univerise holds this as absolute truth, because there is nothing to contradict that 2+2=4.

Answer 2

because my kindergarten teacher said so.

Answer 3

We are not stupid. So..

Answer 4

Haha!...I laughed at myself for answering this question. Of course 2 + 2 = 4.What makes you think that it is not??....

Answer 5

Who knows?

Answer 6

Since this is in the Zurich category, because the teacher or the policeman or your Hauswart said so.