How much is 1 plus 1?

Answer 1

When working with numbers the way people do in everyday life 1+1=2.

However, there are times and circumstances when the result is different. For example, 1 pile of sand put together with another pile of sand equals ONE pile of sand, so then it would be correct to say that 1+1=1.

Or, if you are working in binary arithmetic, where only ones and zeros are used, and the expression "10" is equivalent to the number two, then 1+1=10.

Or, if you are considering rotations through pi radians (180 degrees), 1 + 1 = 0. Similarly if you consider flipping a switch.