Onenote equations and variables

[debun]

So onenote is really great writing equations but can it actually solve them? I inserted the default equation for the area of a circle but I can’t seem to define the variable r. Even if I replace r with a number it still won’t spit out an answer or recognize pi. Solve for “variable name” only seems to change the subject or the formula not actually compute it. What am I doing wrong?