I suggest you look up the mathematical meaning of a tilde (~)
"Approximation" is only one of the meanings, it can also be used to show an equivalence. Thus, writing "number of deaths ~ 0 " could just as easily be interpreted as "The number of deaths is equivalent to zero" as "The number of deaths is around zero".
In logic expressions, I understand (but have never personally used) the tilde to mean negation, so writing "number of deaths ~ 0 " would mean that the number of deaths does not equal zero. Now, this is generally used with proving / disproving mathematical propositions rather than to showing a mathematical formula, but it's equally valid and would further add to the confusion in your use of the symbol as a shorthand.
If you want clarity, can I recommend "number of deaths ≃ 0 ".
However, as you have suggested learning opportunities, can I recommend some English revision as well as the Maths. Maybe words like disdain, patronise or condescension would be good places to start.