Here is a behavior of the Mathematica front end which confuses me. Type
N[Sqrt[2]]
The displayed output is
1.41421
Highlight that number with the mouse, copy it to the clipboard and then paste it on a newline within the notebook. You'll get
1.4142135623730951`
After this, continue typing to produce
1.4142135623730951`+1
Evaluate this, and you get
1.
By trial and error, I have learned that I get the right answer by deleting the back-quote:
1.4142135623730951 + 1
evaluates to
2.41421
Why? What does the back-quote mean internally?
