Is there a calculator with LaTeX-syntax?

Question

When I write math in LaTeX I often need to perform simple arithmetic on numbers in my LaTeX source, like 515.1544 + 454 = ???.

I usually copy-paste the

Answer 1

Emacs calc-mode accepts latex-input. I use it daily. Press "d", followed by "L" to enter latex input mode. Press "'" to open a prompt where you can paste your tex.

Anyone saing it is not possible is wrong.