How to read this number: 2 - 3e-4

Question

e in this case is not the euler number. Would I read this number, $$2 - 3e-4$$, as $$2 - 3 * 10^{-4}?$$

thanks

Answer 1

Question: $$ 2-3e-4 $$

Using pure mathematical notation, this is two subtractions, so the order of operations (and left to right) suggests the answer is: $$-2-3e$$ where $e$ is Euler's number.

However, in many programming languages, and in calculators, $E$ or $e$ is used to denote orders of magnitude, so: $$ 2-3e-4 = 2-3(10)^{-4}$$

I would argue that the later is intended, as otherwise a simplification would have been made to the former. But,if this is part of a calculation, it may be laid out like this for ease of seeing the steps taken. e.g. for $x=2$ $$x-3e-x^2$$ $$= 2-3e-4$$ Therefore, more context is required, but it is fairly safe to guess the order of magnitude option is intended.