Modular arithmetic

Questions
1

I don’t know if mymemory is failing me but I can’t seem ti be able to render correctly some simple modular arithmetic in latex :

Example

content:
"
7 \equiv 16 \pmod{3}

"

I typed all kind of variation but I never get to display properly in the notes.

2

Desmos doesn’t use the full latex formatting. I think it’s MathQuill if I’m not mistaken. I’d just search for the equivalence symbol and copy paste it. It looks like it’s just a note, and full-on latex formatting shouldn’t matter a whole lot:

7≡16 mod(3)